its commonly known whoever has position has the advantage, they have the ability to see how their opponents react and then make an informed decision.

why in chess where white acts first, is said to have the advantage? is it not comparable due to poker being a game of incomplete information and chess being a game with no unknowns?

I find in plo that being first to act in big pots serves as an advantage sometimes. ie in multiway pots you can get some weaker non nutted draws to fold and close one pair hands to fold, provided you are looking for folds. in heads up pots i notice you can have first bluffing rights on certain boards.

how much does position matter in general in poker, in plo?
i know its a super vague question, not looking to open a 10 page thread but maybe some people could bring some important points to light off the top of their head?

thanks,

Yes

Definitely not.

Why can't you do that if you're later to act? You can get even more folds because you know players are likely to have weaker hands, and lose less money betting into stronger hands.

For an indication of the importance of position, if you're 250bbs in PLO in the SB, and someone raises, then someone else 3bets, you actually fold some AAxx in the SB. You never fold any of them on the button.

Chess is different to poker, because a chess game can finish after one "ply". There's no chance to make a response if your (white) opponent checkmates you on his 4th move. The game is just over, even though you've only made three moves as black.
In poker, the opponent always has a chance to respond to a bet, check, or raise. This means the ability to act last is advantageous. Being able to close the action (or fold without investing any money, when you have a bad hand) is extremely valuable, and it's only in rare spots where being first to act is best.

FWIW, game theory studies have shown that acting first in multiway spots in particular is especially disadvantageous. Usually whoever bets first is "donating" free EV to everyone else. If someone donks into me multiway, and another player raises, I fold all my bad hands for no loss at all, as the donking allows me to avoid firing money into the abyss with a c-bet that wouldn't have worked.
Similarly, I'd rather have a hand like TT on the button than UTG. If I open UTG, then there's 5+ players that can 3-bet/4-bet me. The hand is much more valuable if 3 or 4 players have already folded.