I bought them ages ago and let me tell you, crazy taxi without the offspring is just not the same. Borrowing the original versions for free from the internet is the only way to go.
I am pretty sure I picked up the Android version for free a few years ago and it had The Offspring but I installed it just now and it's gone. It's also now talking about ads and data collection so I assume the original build has been unavailable for a while.
Exactly, they announced earlier this year that they were working on reviving a bunch of licences, including Crazy Taxi, Jet Set Radio, Shinobi, Golden Axe, Streets of Rage, and hinting at a longer list. We don't know yet eactly how many titles that includes, and which of them will get remakes, remasters, or brand new games, but it was hinting brand new. Early dev footage was leaked at some point for Crazy Taxi and Shinobi.
I wonder if it's a licensing thing. I know a few of these games had heavy use of licensed music, like Jet Set Radio and Crazy Taxy. At least, the original versions did, I'm not sure if that's the case for the Steam ports.
Sometimes they're not on gog and I want to play them. Other times it's 4$ on steam and 50$ on gog. I'll buy it for 4 on steam so I can play it, then wait for the sale on gog down the road. Sometimes it's a convenience thing cause I have a steam deck and it's just nice to deal with native compatibility.
No, you need to install them as well. It'll work as long as it's installed, but after they're delisted, I don't think steam can even distribute them.
I know I have at least one game "grid: race driver" that was delisted from steam, at some point I must have uninstalled it, and now I can't download it, it doesn't even show up in my library. I've been trying like hell to find a way to play it, but even pirated versions are being difficult.
Edit: judging from comments and downvotes, apparently this is rare? But it does definitely happen, I'm not making this example up. And I don't know how you could predict whether a game will just be unavailable for purchase or totally disappear...
That's the Sega Genesis/Mega Drive Classics collection. I have it myself (bought several years ago). It's just an official emulator/GUI wrapper (styled like a bedroom with a CRT) that comes with the games. If you have the collection you can find all the ROMs in the collection's folder and play them with whatever emulator you want. If Steam ever threatens to take them away I strongly recommend backing that folder up somewhere.
That's games that you can and do buy of Steam. Delisting changes nothing except that you won't be able to give them money in exchange for not owning the games.