Well you are rarely more than 55-65% favourite on preflop alllin. Except when getting in with e.g. AAxx Vs AKKx where it will be bit over 70%.
Biggest edge comes at least in these games from preflop hand selection. Pool play way too many hands and often with passive lines. Meaning they won't win pots as often as there is less possibility for it preflop. Also hands they play often for multiway pots are not really suitable ones. Meaning having nut potential. Preflop poor hand selection then reflects heavily into postflop.
Tables with lot of multiway pots you can't really get too much out of line postflop as often someone has hit and likely continues. But with better build ranges you will get into spots where you have better sets, better two pairs and better draws. Those are moments where money can get in way ahead.
3bet game especially is really heavily build around choosing solid ranges. Often in them SPR is on low side on flop and money goes often in. So when some of even reggy players choose to 3bet so called raggy double suited hands they will in long run run into spots where they are too often dominated. Same happens when calling 3bets and 4bets way too wide.












