(Sorry, this is very long and rambly... just some thoughts I had after reading the last few posts here.)
Regarding the long-term availability and security of digital game accounts (mainly Steam), I think at some point you have to treat it as an important asset that needs some extra care taken to protect it. It is a huge mistake for people to treat a digital collection of purchased games like any random throw-away account on a website they never intend to return to. But the same can be said for a physical game collection. It all takes effort if you actually care about the stuff.
People with boxed game collections (or any other collections) have to do something to ensure they are stored and cared for properly. If you aren't careful with the disks, they can be scratched and rendered useless. If you stuff all your boxes in a shed, garage, basement or attic they are likely to get moldy or at least get smelly or warped from the heat\cold or humidity changes. Worst case scenario, pests can get to them, which is really nasty and very sad when it happens. Rather frustratingly, the other extreme is that having the boxes out in the open and exposed to sunlight or fluorescent light (less common these days) will discolor them fairly quickly as well. So you need considerable space to dedicate to store a large collection, and unless you live in a very favorable climate (dry and moderate temp year round), you will be dedicating what would otherwise be heated\air-conditioned living space for them.
Considering digital game collections can easily run into the 500-1000 game range if you've been buying indie games and bundles for 20+ years, you'd need a huge area to store an equivalent number of physical games properly. Of course, we're leaving out the fact that effectively zero percent of PC games have had physical boxed releases in the past 10 years.
I think No Man's Sky was the last PC game I bought (back in 2016) that even had a physical release... and I bought that on Steam. It is also an interesting example of the relationship between digital releases and physical releases. The game was really underwhelming when it was released but has turned into an amazing game-dev redemption story since then. If you have a physical copy, the version on the disk is so poor and lacking so many features compared to the recent versions that it is hard to even call it finished. Of course, from a historical preservation perspective... if you want to see the original release version just for comparison, that is usually harder to do... but with NMS specifically, this project allows you to play the older versions. PC gaming is definitely the best gaming. 😀
Anyway... As others have mentioned, there are ways to make a lot of Steam games available offline, in addition to the ones that already just work without Steam if you run the .exe file directly. Lately, I have also been curious about doing a backup of the Steam folder when in offline mode and then storing that somewhere. I don't know how that works exactly, but I feel like if offline mode works at all (which it does) then directly copying the folder and maybe the registry keys would allow you to have a functional offline copy of Steam if it ever got really dire.
As far as security is concerned, that is an area that everyone should take seriously... but they probably don't. I'm sure some have digital game collections that are worth more than what they have in the checking account at any given time... so treat them the way you would a bank account. Your Steam, Epic and GoG accounts should all have proper MFA and some kind of backup methods for verification on hand. It is so so so much harder for someone to "hack" (ie, trick you into giving them access to) an account if you have proper MFA set up.
Even the old fashioned "send a text before letting a new device sign in" is infinitely better than just having an account secured with a password or a Google\Apple sign in that may or may not have great MFA on it either. If you use your cell phone number for 2FA though, make sure your account is set up with SIM swap protection. It's easy to turn on with most carriers and basically eliminates the main way that text-based 2FA can be compromised (other than social engineering attacks at least).
In short: I still buy and collect physical music CDs and store them in a big box, but I have only kept a small number of PC game boxes. I am glad that the hundreds of indie games I've purchased over the years do not need to be stored in my home and cared for, and I am happy to go through the extra steps to secure my accounts and make whatever kinds of backups I can to protect my digital PC game collection. I do not think that console gaming offers any of the same options as PC gaming though, so digital only console gaming is something I imagine people will regret giving into once they are feeling nostalgic in 20 years.
EDIT: After looking more at the old-version downloader for NMS I discovered something that I had never heard of before. For years it has been possible to download old versions of games through Steam using the "Download Depot". A somewhat more accessible way to do it would be with this program called "Depot_Downloader". I have not tried it myself, so use at your own risk (make sure you are using SteamGuard, etc.)... but it looks like it has been around a while and is an interesting tool for those interested in game preservation.
Now for some blitting from the back buffer.
