I think it's a great game but... If you're already bored with it now, in Route A, it's not worth continuing in my opinion, and I say this as someone who liked the game.
The reason I'm saying this is because of Route B. The game has 3 stories, the problem is... the second one, route B, is actually nearly identical to the first one, but worse because you're playing with 9S and half of the combat gameplay is removed, replaced by some hacking mini game. It's really bad and very, very repetitive to go through the same thing again but in a worse version.
Route B is really my main huge problem with this game, I will never understand why they did this, because route C, the third story, is actually the real sequel to route A, it's a whole new thing, like the second half of the story, and you get to play with the best character there (A2), but I think a lot of people never even saw this because when they saw route B being the same game again, they probably thought it was just some bonus new game plus that wasn't worth it. Terrible game design decision in my opion.
I still really loved this game, the combats, if you do try to play well and have fun with it, are great. You are never required to do crazy combo and be super skilled, so that may be why people don't think it's that deep, it's only up to you to make your own fun with the gameplay, the game itself doesn't force you to use the whole gameplay. If you're not interesting in having fun with the gameplay outside of what's "required" by the game, then I think it's not worth it to keep playing for the gameplay either, but at the same time, I think someone interested in gameplay in general would be interested in doing fun combos etc in this game without the game forcing you to.
The parts with A2 in Route C were my favorite part of the game, I was just disappointed that route C forces you to often go back to 9S AGAIN, it really felt like the game was trolling me, locking me out of the good gameplay over and over, it was quite frustrating... But there are so many other great qualities that I can't hate the game as a whole, even if I do hate how much the game forces 9S.
My favorite part was actually playing the DLC arena post game with A2, that's where the whole gameplay was unlocked and you could do anything, it was super satisfying. I wish more of the game was like this, because I don't think I would feel like replaying this game again, since the game itself already require you to play in a loop with a lot of repetition before getting to the good stuff.