I think you're hitting on a slightly broader problem. Any game where combat is the major mechanic shouldn't have a situation where you can't do any damage for any extended amount of time. The Yakuza series handles this well, enemies can block, but the moment they do you have attacks that can break the block immediately, and start damaging again. (Or you can skill up to that that attack.) As the game goes on, it gets more intricate, different enemies have different blocks that require different moves to break. The player character also has different fighting styles that have different block breaking moves that you have to keep track of, but if you know what you're doing, you can break almost ANY block with one move.

Far far too many other games decide to arbitrarily create a mechanic where you can't do any damage for a WHILE. It's either the invincible enemy that you just have to spend 3 minutes dodging, which is boring and miserable in both action and even turn based RPG battles. Or they have a shield that you have to do some elaborate and rhythm breaking routine to remove the shield. It's a miserable slog whenever they do that kind of thing. Back in the early 2000s The second game of the Xenosaga trilogy changed the entire combat design and added the thing I hate most, the RPG stagger. You can do no appreciable damage to any thing in the game until you figure out what combination of attacks cause a stagger. It could be a three move sequence involving two characters that has to be done in the right order, or woops! Start all over. If you didn't give one of your characters a specific ability or attack during leveling, screw you, you're basically fucked.

The players, rightfully, rejected that crap then and they got rid of it for the third game. Now, it's everywhere. Every RPG I've played recently has that crap. I finally just put down FFVII Rebirth half way through and said, screw this, because it was so exhausting and miserable. Every battle becomes the equivalent of getting on a non-working escalator and your body still jerks because you think you're going to start moving. I hate this trend and it's everywhere as developers think, "this battle isn't bossy enough." "Add a stagger mechanic to make it last longer" "Brilliant old chap."

I don't know what disease is moving through the game development community that boss battles, especially, have to be a certain length. Is this a marketing thing? Is this being handed down from the publishing execs? FFXVI had 20-25 minute battles towards the end that were just repetitive dodging and a kaleidoscope of flashing lights. I could have just had a gummy and watched an old screensaver and it would be more memorable and less annoying.

Okay, I'm done complaining, but the long battle for no reason other than to make it feel like a boss, is, I think, an extension of the collect-a-thon, open world, sandbox mentality that just adds superfluous crap so they can say "This game is 44% larger than the last game we made, and will take you 215 hours to complete!" Who cares if it sucks?