I'm not sure how Linux and Windows even came into this thread. The original post is about a Pentium 200 being enough for the tasks it was designed to do. Neither modern Windows or Linux will run (or run well, in the case of Linux, it will maybe boot...) on such hardware, as a result of both platform's severe bloat, particularly in the GUI department, but also background programs.
Basic office utilities should not require a multi-dozen-billion-instruction-per-second CPU to run (looking at Libreoffice and Office equally, LO is a bit lighter but not tremendously so), OSes should not suddenly decide that perfectly good hardware that's about 5 years old should be cut off from support (looking at Win11), OSes shouldn't require OpenGL acceleration for their GUIs, which do almost nothing but draw flat colorful rectangles anyway (looking at any number of Linux DEs)
At some point the level of bloat at the OS level is surely going to have to be re-examined, it's getting somewhat out of control. Multiple gigabytes of RAM shouldn't be in use at idle, even with background programs running, unless it's maybe as a disk cache. It's a severe and continuing ridiculous waste of computing resources. GNOME introduced a new feature recently that adds triple-buffering so it can take your GPU out of idle if it can't keep up with rendering the GUI! It almost sounds like satire but it's true. I'm sure Windows has had that trick for years though, considering my memories of PCs barfing at the load of Aero.
Almost all the hardware progress that has been made in the past ~20 years has been completely negated by the absolute crumminess of the software we run, whether it's developed behind closed doors (MS) or in the open (Linux). A PC from 2002 would have no issue doing almost anything we do today. It may struggle a little bit with the more advanced video codecs and high resolutions but soften it up with a little hardware acceleration and it would be no big deal. Discord, Steam, Facebook, Twitter, VOGONS, Snapchat, Instagram, whatever, would work fine if they weren't all piles of Javascript and Chrome now, layers of interpretation and JITs on top of layers of interpretation and JITs. Almost nothing any of us do has a meaningful benefit from the obscene computing power available to use today (well, maybe not us in particular, emulation and virtual machines are pretty heavy).
Dan Gookin said in one of his editions of PCs for Dummies from I think ~1999, about PC upgrades, something along the lines of "Consider carefully if your PC really needs an upgrade for what you're doing - A faster computer won't make you write documents any faster if you're already limited by your typing speed, and it won't make your grammar or spellcheck any better."
Only hardware upgrades that have really made a big difference to anything: flash storage and faster (and faster and faster) internet speeds. And cellular data and computer-phones being made possible by the continuing march of miniaturization, I guess.