You mean your Zora's Tunic, right?

(That tunic prevents you from drowning. It's actually not required (especially if you have a lot of hearts), but it does remove the time limit.)

Aside from the boss, the only issue I have with the Water Temple is that it is annoying to (un)equip the Iron Boots, which you have to do repeatedly in that dungeon; they should have made those boots a C-button item so you wouldn't have to open the menu every single time.

Nope, your reply was based on what you want, which I also don't care about. You're only seeing what you want to see. There are plenty of user reviews which complain about games being unnecessarily drawn-out, and plenty of reviews being happy about shorter games. But that doesn't align with your views, so you're just filtering them out. If devs hear from people wanting shorter games, then devs hear from people wanting shorter games. It's not a "lie", that's just the way it is, so maybe you should deal with it, eh? It doesn't mean that long games are going away, obviously there's demand for that too.

The problem with the OoT Water Temple boss fight is that, when you get hit by the boss, the boss will throw you around while damaging you, and there's nothing you can do except wait. In other words, the game takes control away from you when you get hit, which is incredibly frustrating.

(The dungeon's mid boss doesn't have this issue, and I don't think the belly boss does, either.)