Is it worth studying poker seriously or just play and learn?

never really got why people say you have to study poker hardcore, like with spreadsheets and training sites and all that. i mean, i get it with blackjack, where the edge is razor thin and execution matters, but poker just seems more about reading people, adapting and getting reps in. i’m not knocking work ethic at all, i just wonder if there’s a point where it’s all theory and not enough table time. most people i know who grind poker just play a ton, keep notes on tendencies, and adjust on the fly.

has anyone actually seen a big jump in profit after doing a ton of study, or is it just better to treat it as learn-by-fire and adjust as you go?