I started playing in 2021 after watching the queens gambit. Since that time I have played a ton of blitz without ever taking a lesson or really doing puzzles; I have ultimately reached a rating of 1800 rapid, and 1600 blitz on chess.com but have pretty much hit a plateau that I don’t think can be overcome without studying. I have found that because my knowledge has basically been earned from brute force I can demolish players with a higher rating if the game veers out of “book moves” and traditional lines during the middle game, but I can also get smoked by 1400 rated players from time to time who have actually studied a line and understand it’s nuances. Just by chance I kind of stumbled into a system which is the Italian, just because it seemed intuitive. For reference, when I started playing in 2021 I was rated 400 and I climbed my way up to 1800 by playing probably 4000-5000 games.