I have major regret for buying this game. Games like this should have a 20 hour refund window instead of 2. It took me 2 hours to realize it wasn't possible to get the game to not run like garbage.
Well if the companies refuse to give you a demo to try, maybe you should pirate it to try and then purchase it.
Another option is becoming a patient gamer and just waiting for the game to get better (if it does) a year or two down the line and then buy it at a discount.
In the last few years there aren't many games I didnt regret buying early.
Perhaps Steam's policy should be 2 hours or 10% of expected playtime as set by the devs, whichever is greater, perhaps with a max of 10 hours. That seems pretty reasonable to me.