Because I've wondered about that too. Like, right now there's a pretty big dichotomy between "purchase and play a game myself" and "watch someone else play it on youtube/twitch". But it would be interesting if there was a market for a kind of interactive guided tour, like for $10 let me play the best 4-6 hours of AC:Odyssey, and that's delivered as a mod that just trims all the fat, levels me up quickly enough to hustle through the main story beats and see the good boss encounters and action set pieces.
(Ubisoft themselves sort of do this with their paid XP boosters, but that doesn't actually cut content, it just lets you skip a few hours of grinding over what is otherwise still a 40hr+ experience for most people)
That said, I'd imagine a fair chunk of the impact of major set pieces and end bosses is that you've spent many hours to get to that point. An abridged version would have to leave bough in to allow emotional investment in the story. This is still possible.
Gamers Digest? (For those of you who remember Reader's Digest).
So I'm not willing to pay a premium for such a thing. I don't see why the game with the bad part missing should be worth more than with the bad part present. Rather, the inverse! I'll more likely skip the game entirely and find a different one that doesn't have such mandatory grinding.
As I say maybe that's an outlying opinion since making money from this kind of thing apparently works. It it helps, I'm in the adult with family demographic and my time (rather than game purchase levels of money) is what is at a premium.
So rather than pay US$70 today for a buggy, grindy new release experience, I pay $20 in two years for the base game + $10 for the "player's digest" mod.
I expect even then it would be a tough sell, particularly having to be on PC— a lot of the market for this kind of thing would more casual console/mobile/streaming players.
The abridgement thing sounds like a smart approach, but ultimately I've gotten more enjoyment from shorter games that don't pack the fat in to begin with.