I've seen and heard many people say that the Catalan is slow, the Catalan is boring, the Catalan is just a stupid Fianchetto and a way to avoid theory of main lines, but all of that couldn't be farther from the truth. The Catalan, if in the right hands, can absolutely decimate your opponents. I chose this as my main opening and have been extremely impressed by the sharpness of this opening. Rather than going for an immediate, obvious attack in other openings (Ex: King's Indian Attack, King's Gambit, etc), the Catalan prefers to attack with subtlety. The long term, sustained pressure on black's queenside will, if facing someone unaware, cause their position to crumble. The Catalan is a very theory heavy opening, but the plans are extremely flexible. Many positions can often transpose, and most of the theoretical moves of the Catalan are actually quite obvious.
Here's an example of a line where black overextends by being too greedy and attempts to retain a material advantage
(Apologies for spelling errors, chess.com won't let me edit annotations for some reason)
(This is only one line of the Open Catalan btw)