Hence dot files

Granted, a lot of home PCs and gaming PCs are single-user environments. The “personal” computer. In that case there’s no reason games and applications can’t be installed in %LOCALAPPADATA%, and in fact, I think windows has an environment variable or registry setting for that.

I tried setting up my main windows gaming machine with a separate admin and user accounts, and tried to set it up to be multi-user. It didn't work well. Most games worked but some random games had all sorts of bizarre issues, from only being able to run as admin, to requiring messing with directory permissions to just plain strange behavior but working sometimes. Steam also really didn't like if I tried to run games as a different user and got very confused at times by the multiple user accounts

My Documents > My Games is kinda the default, but then you have steam cloud syncing and tons of games that default to various Appdata folder seemingly at random.

There is, been there since 7. Just hardly any game Devs use it, including Microsoft.

C:\Users\Username\Saved Games is a thing. Not a lot of games use it though.

There's also C:\Users\Username\Documents\My Games which seems more popular with some devs. Though some devs inexplicably use the base Documents folder, which is just obnoxious.

But yeah, a lot of devs still use AppData. I read a post from a dev once that explained the advantages and disadvantages to each Directory, though I can't remember the specifics, there is at least logic to why saves get stored in so many odd locations.