Get ready for an extremely long and complicated answer.....
I use both new AND old hardware, and emulators, and source ports. There are pros and cons to both. This gives me flexibility to use whichever is the most efficient solution without always having to sacrifice the experience. That's sort of what it's becoming more about for me as a married man who is almost 40 and has a career.
First off, I love love love love love old hardware! Love it. Especially the 486 era. And I have over 20 years experience accumulated messing with it from back when all this stuff was called "Door stops" "dinosaurs" and "boat anchors" by people. So really for me, the original hardware - at least for games 1981-1997 - is the way to go because it's the least fiddly for me. Also, I have some DEEP nostalgia because I grew up in that magical time of DOS games, when computers "are the future" and this stuff was "mysterious" and "Made of magic" to most people. There's just nothing to me like sitting in front of a big beige box, with another big beige box next to or on top of it, with a big ole clacky keyboard, and a solid, heavy mouse or trackball, and some kind of awesome multi-button gamepad with FM and 8/16-bit digital audio + my own CD soundtrack blasting from the speakers.....or turning up on my patio or at the local coffee house with an old gray TFT equipped laptop rocking out to Nirvana on headphones and playing Wolfenstein like it's 1993, or surfing in Links.
Granted, these old boxes are not 100% accurate. I pretty much tune/tweak/mod out all the "inconveniences" and "Annoyances" they have. All my HDD are caddied, all my systems that can use them have optical drives (basically anything 286+), I have the fastest video card I can jam in the case and find for cheap in them, with the VRAM maxxed out. My laptops get their batteries rejuvinated or rebuilt so they are actually portable and their HDD upgraded to SSDs or accelerometer equipped models. So what I end up with is a quasi-accurate experience with a CRT and all the other tactile and aesthetic stuff - except slow load times, or even needing the CD at all, loud HDD, loud fans, needing to drag an AC Adapter with me all the time. I'd say my hardware skills are - at risk of sounding conceited - god tier, new or old. And the newer the system, the less I have to do. I find anything 1997 or later pretty boring. I can get out of it what I want with ease, and pretty much use it as a day-to-day PC.....I like the challenge with low risk of getting an 80486 to do things most people need a 64-bit dual core CPU and 8GB of RAM to do. I can build a fully running retro-rig faster than I can tweak or tune an emulator or sourceport.
But a major monkey wrench is on a software by software basis....
Most anything post 1997 I'll try to run on Windows 10 first, either via compatibility mode, or directly. I'm finding more and more of that stuff stopped working, hence now building out an XP based P4 box.
For example, The Sims 1 - I have to tune and tweak it after I install it on my Windows 10 computer so it'll handle the newer higher resolution, and even then, it tends to be buggy because it's some user-designed patch for a commercial AAA title. So why bother? I can slap it on my P4 in 20 minutes - with all expansions - and be done with it, and I don't need to do anything but apply the no CD-patch, which is just copy/paste another EXE into the directory.
Another example would be Ultima VII parts 1 & 2. I love Exult, but to me, all that extra "candy" of having the SIlver Seed and Forge of Virtue add-ins + god mode + the ability to build things, + hackmover and being able to have higher resolutions and see more of the m ap tends to lead me down a different playing path and thusly a different experience. But I can also put them on a Win95 box and use U7dpmi to run in Windows 9x without a hitch or rebooting into MS-DOS mode. Or I can go truly oldschool and install on my 80486 in DOS and build a special boot option for it (if needed, I'm pretty good at memory management in DOS at this point).
Or you have the old Scumm Games - for example, The Secret of Monkey Island - you have THREE options there too: The Steam RElease with the updated graphics and speech, SCUMMVM in Windows, and the original releases from the 90's. I've never played the steam release, but I'm, to be honest, not that happy with the new graphics. Sure, they look great, but to me, my connection with Monkey Island is kind of special because it was the first PC game I ever got into, I like the original VGA artwork best. But sure, I Can change to that too.....but another thing is.....I have a 286, 3 486es, 2 Pentiums, and the option of ScummVM on the P4 or any of my modern computers + 2 wii and Rpi4, so why would I want to spend $10 of money - that's ingredients for dinner for us - with THAT many options on my plate for Monkey Island. So I just install it on everything and jump around systems like a maniac One minor inconvenience of the original hardware is I have to pull out the Dial-A-Pirate wheel or ring up the virtual one via google search when playing on original hardware - ScummVM disables that issue, but it's also part of the experience. So it just depends on if I want to mess with the wheel or not. I dunno, it just feels best with that code-wheel and an old beige desktop like when I was a kid in 1992 on my sister's old 386. TBH, I really hate playing ScummVM on the Wii because the Wiimote makes my arm hurt if I'm playing for an extended period.
Also, sometimes I find certain systems are more fun to play a certain title on. I prefer Elfland on my 286 for example. TankWars as well because of the hilarious speaker sounds and a 486 speeds it up a bit much. But I prefer Ultima VI on a 486 because it goes so fast I can literally speedrun that game on it - it's just fast enough to do things super fast, but just slow enough to be playable comfortably. I tend to prefer the Windows 3.1 port of SIm City the most, as it's color, but I can cheat more easily in DOS by slapping it on a DX4 and letting it run over night once I build a good steady model of monetary growth if I'm in a "build without limits" mood. I quite enjoy Ultima 7 on Exult though because it's fun (and downright hilarious) sometimes to go full "Doug The Eagle/IT-HE" on it with the hackmover and other tools - just forgo the opening puzzle, attack Batlin and fill the screen with guards because he never dies - just keeps screaming. Cast apocalypse. Ransack shops, build my own house - just so much fun. But then I can do ALL of that with Doug's tools in Ultima VI on a 486 in DOS....
Sometimes it's also how I prefer to play the title. For example, I game with my Wife, and she's less likely to want to hang out at a computer desk with me in front of a 15" CRT than she is sitting on the couch in front of a 52" TV with a Wii or RetroPie. But it's a double edged sword because people not into this then I have to teach them a controller where the controls are not immediatley obvious - then I kind of WANT to setup on the old hardware because there was a certain logic there that was universa vs. my own inner logic that someone else might think is ridiculous for a controller layout.
But this also grants something else nobody ever thought of....if I Can get them all to network together, I can have one heck of a Doom/Quake/Wolfenstein LAN party at my home if I wanted to.
So there's no hard-fast rule for anything, I just use what's best for the situation, and what's most convenient, or what I'm in the mood to use at the moment. IT's chaotic, sometimes illogical, but it's fun, and sometimes I learn cool stuff, and that's the whole point of it for me.