You have probably seen a phenomenon in online poker forums: a user posts a hand where they make a loose call preflop, find themselves facing a tough decision postflop and ask for advice. The top comments are simply "fold pre." What is going on and why do you need to fold pre?
1) Good preflop decisions make postflop straightforward.
Most postflop mistakes are set up before the flop. If you are playing the right hands then you will be in a solid position postflop. If you play the wrong hands (especially if you are calling with too many weak hands) you will be in a world of difficulty postflop with your marginal holdings.
When you are still getting to grips with postflop play, hands like top pair with a good kicker, an overpair, or a set are very forgiving. You know roughly where you stand and will often have a strong value hand you can confidently bet. When you completely miss, e.g. AKss on T97hhh, it is easy to check fold. You will still make mistakes, but can nevertheless be a winning player because you have a massive advantage by playing stronger hands than your opponents.
What you really want to avoid is situations where you have a marginal hand like weak top pair or a weak draw facing aggression. This is where players bleed money.
2) The rake at low stakes discourages wide play.
Rake matters a lot more at low stakes than most beginners realise. At higher stakes the rake is a rounding error. At 1/2 it is a constant tax on every pot you play and it falls hardest on small pots, which are exactly the pots that wide passive players create by limping in with speculative hands.
If you are playing 40% of hands and regularly seeing multiway limped flops, a significant portion of your poker activity is happening in the worst possible rake conditions. You are not just playing marginally profitable hands, you are playing them in an environment specifically designed to make marginal plays unprofitable.
The tighter you play and the more you build pots with your strongest hands, the less the rake hurts you. You are paying it in fewer pots and winning a bigger share of the ones you do play.
3) In multiway pots, marginal hands are a mirage.
When six people see the flop (not unknown in live 1/2 games) the hand strength needed to put chips in rises enormously compared to heads up pots.
Weak offsuit aces, unsuited connectors and suited gappers like A6o, 98o and 95s play extremely poorly in multiway spots because they will often flop marginal pairs or dominated draws. You will face tough decisions with weak pairs, and sometimes make a straight or flush that is dead to a higher straight or flush.
Hands like pocket pairs and suited aces play well multiway because they can make nutted hands like sets and nut flushes that will rarely be dominated and can win big pots.
But everyone else is loose and bad at poker. Can I not just play loose as well?
Everyone else is losing so if you imitate their playing style you will see similar results. The optimal strategy in poker is generally not copying people who are making mistakes. Your opponents who play 66% of hands in a full ring game are not winning players. The correct response to wide passive opponents is to tighten up, wait for strong hands and value bet aggressively.
As you improve and develop your postflop skills you can start to open up your range, particularly in position against recreational players who are going to pay you off when you hit and give up easily when they miss. But that is a later conversation. Get the fundamentals right first.
If you want a clearer picture of which hands are actually profitable to play from each position, and why certain spots go wrong postflop, QuintAce.ai breaks this down in detail. Introduction to the platform here: https://quintace.ai/blog/quintace/what-is-quintace-a-complete-guide-to-the-platform