No one wants a 20 hour empty game. A 20 hour game needs to be dense, like a good book of equal length. It needs a compelling narrative and interesting immersive gameplay. A 20 hour game can get away with immersion adding limitations to parts of it that an 80 hour game can't, stuff like not having quick save is annoying in an 80 hour game but perfectly valid in a 20 hour one, same with point of no returns, very grating in 80 hour games but perfectly fine in a 20 hour one.

Also I don't consider Open World to be a type or genre of MMOs, I'm exclusively talking about Ubisoft style open world games like Assassin's Creed and games obviously inspired by that open world approach. For MMOs busy work is good because the point really is to socialize and all content is good basically. If the game has co-op then I'm much more lenient on the busy work aspect.

Further I'm also only harping about story less or with very limited story tied to it type events. Like the cop events in Cyberpunk 2077 which is basically an ongoing crime and for whatever reason you have them marked, can go there and kill everybody, get some small reward and a thank you message. But it more or less clashes with the story overall and there's no point to it. Having enemies to kill and things happening in the world is of course a good thing but drawing player attention to it with an icon and interaction like the thank you message creates expectations about a payoff or it actually being meaningful outside of "clearing the map". But it's not. It's also a fact that crafting all of it takes time, time better spent on making the content that is meaningful even better. Basically give me one 1 hour mission rather than six 10 minute ones.