tests of skill and ability are inherently ableist. There are plenty of games that allow pausing, they’re the majority, even. Let people have some that don’t for artistic or ludic purposes.
"Let us have a little ableism, as a treat."
The thing is, it doesn't need to be either/or.
I could try to get those to stop being made or i can go play any of the thousands of other games that aren’t like that
Or devs could do the same thing they've been doing for decades with difficulty levels. Before the start of a game, let users choose the difficulty levels and that could include whether or not they can pause the game. Users who wish to can then pause. This can be locked into the entirety of that playthrough. Problem solved.
Games almost never have to actually choose between ableism and the dev's vision for difficulty or pacing or whatever the fuck. Just give people the option. Hell, it would encourage people like me who struggle with difficult games to experience the game the way I am able, then try it again with higher difficulty (without being able to pause) rather than simply never being able to experience the game in the first place.
Given the reasons you listed why you can't play certain games, wouldn't you appreciate it if devs made the game in such a way where you could still choose to play it in the way you can, and let others play it as is? Obviously this isn't possible in all cases, and some while possible might require such a huge revamp of the game that it would effectively be a different game. This is not the case for simply being able to pause the game.
This isn't a lot to ask of devs for large masses of people who live lives where they will have to step away from a game without notice but would also like to not be punished by the game for doing so or outright unable to play it because of that life.