I started studying GTO a little while ago, and let me tell you: I was blown away by the number of mistakes I was—and still am—making in my game. Anyone who thinks they don't need to study is sorely mistaken. Here’s an example: have you ever studied how to play against a 5-bet? It’s an uncommon situation, but the first time I studied how to react to a 5-bet, I got it wrong all ten times I tried. In short, study so you can stop complaining about cashing (making the money) but failing to reach the final table or semi-final. GG.
Its not that uncommon especially in wide range spots e.g. SB v BU.... however the charts assume your opponent is 5 betting at the correct frequency, which almost no one is at low stakes games. E.g. SB v BU, the SB should have some 5bet bluffs like A5s and KJs but its rare to see them in practice