I'm only counting single-player experiences created by humans; which are possible to beat.

In 2017, speedrunner and live-streamer The Mexican Runner set out to beat all 714 official NES titles in his "NES Mania" challenge. The NES was one of the most limited home consoles, sourcing from a time when home gaming was just starting to become a thing, and it took this man almost three years to finish the series.
Now consider the SNES' library with over 1000 more games. The N64. All the PlayStation consoles; the XBox games; and of course the ever-thriving PC indie game scene. The NES 40KB size constraint is a relic of the past. Some video games have 100 hours of content. Some games have stupidly long grinds that take hours.

The biggest obstacle would not even be the really challenging games; or those with really long grinds. It would be the shear volume of content. Most would spend far longer on short games that you can complete in a few attempts, than on anything that would be a severe challenge to the average "gamer".

This is very similar to how YouTube gets six hours of new content every second.

Reminds me of the old "You have reached the end of The Internet" commercial.

Can you imagine how much porn that guy watched?

Shit, it's probably not even possible for me to 100% complete every game in my Steam library in my lifetime.

Beat doesn't mean 100%. It could be finish the main story or unlock all playable characters.

Its hardly even possible to 100% OSRS, nobody has done it yet even with tens of thousands of hours played.

Have you heard of the cancelled Penn and Teller video game Desert Bus?

It takes 8 hours to beat, requires your constant attention, and can't be paused. I'd say that still falls into the "possible to beat" but you could keep pushing the limits further.

What if there were 10 levels like that but you can pause between levels? Still technically possible. What about 1000 levels? That requires almost a year of active playtime, but there are pro players with that many hours in their game. Where's the limit? 10K? 50K? 500K? I don't know.

Of course, this is all just a random thought experience on what it means for a game to be possible to beat. I don't think there's an empirical way to define the boundary between possible and impossible, but we could also just restrict it to "games that have been beaten at least once by someone and are provably beatable".

Ultimately I do agree with you though. There are just too many games out there for this to be possible anyway.

I'm doubting I'll even play all my steam games for at least 1 hour...

The PS2 alone has over 4k released games. Even if you remove all the gacha bullshit (there's A LOT), visual novels, re-releases, Phoenix Games shovelware and Japan exclusives, it's still over 2k games. That alone is enough for a lifetime.

Yes I am familiar with Desert Bus. I was thinking of that game and a few based off it when I wrote my second paragraph. That, and the abundance of flash games targeted toward kids.

For "possible to beat" I really mean possible. Not humanly reasonable. If there is a way for a standard human to do it, as difficult as it may be, it counts. Unless the game is unfinished, has no means of completion (like some Action52 games) or is impossible by design—like, the player can not cross a gap impossible—it counts. For stuff that requires staying awake for 100 hours... I suppose stimulants could be provided. That or you switch to polyphasic sleep.