1. The cast is too large to properly spent time on any of the relevant character to the plot. We are introduced to a series of Espadas (the bad guys) and they all seem to have one personality. There are almost a lack of nuance in characterization in this show. It's easy to tell who bad guy and good guy are and I don't see that changing in the future soon. Granted this isn't bad in of itself but then there had to be something that made up for it, but sadly the rest of the shows doesn't make up for itself.
2. Orihime. OH GOD. I know people bitch about Sakura but thanks god she wasn't that very present int he show. This girl on the hand, check every box of a useless shonen female character. Every time Orihime is there it ruin this show for me. It's like she is programmed to only have 2 lines, "Kurosaki-kun" and "don't die". She is useless and though the later arc tried to shape her personality more and give her some OP power, it's very hard to care about her as a character. The rest of Ichigo friend is also a bit too generic and doesn't have much personality beyond "train harder" and "support ichigo".
3. THE PLOT HOLES. dear god, the power system in this show is confusing with all the terms throw around and barely a few liners of explanation. Quincy, Hollow, Arrancar, Adjuchas...etc. But I can take that. I don't mind if a power system is bad but what I do mind is very very convenient plot armor. Example: Ichigo is nerfed by the enemy, but then luckily another enemy wanna fight him so they revive him again. It's hard to take the show seriously when you know the main guy gonna be unscathed because of DEUS EX MACHINA rescue him everytime. There are multiple instances when character should die but the author kept trying hard not to kill anyone. It's too SHONEN for me and it hard to keep me as a viewer invested because at the end of the day, I know 100% the good guys gonna survive.
While there are many negatives to the show, I enjoy the sword power system and the visuals, the music is great, and for an old anime the animation was decent. But compared to other shows like One Piece, Naruto, Demon Slayer, or the god-tier HxH, it's hard to care for this show when other shows had done better in term of plot, power system, characterization.
