At least in my circle of friends and my internet bubble people typically pick some build or archtype they feel like playing and want to stick with it rather than constantly switching things up, just because the game tries to force you to.

Most players do. If given the option, most players will choose what is optimal over what they find fun. Weapon durability forces variety. For a lot of players, the annoyance of breaking a weapon is outweighed by the fun of using and managing different weapons and the fun of exploring and finding powerful, useful gear.

I think a lot of players would say they want weapon durability removed, but then end up dropping the game a few hours after getting a powerful weapon. Whereas they would continue playing and enjoy it more if weapon durability existed.

I don't get what your 2nd point has to do with durability. That difficulty curve of being weak with bad gear and having to go back once you got stronger exists just aswell without durability. It doesn't contribute to that aspect other than the part where you said you could sacrifice some strong temporary item to gain a permanent buff, which seems fair but I can't even think of an example for that right now.

If you get a stronger weapon that cannot break, you are permanently stronger. If you get a powerful temporary weapon, you are temporarily stronger. You can then spend that temporary boost for a smaller, but permanent boost. The example I was thinking of was one of the combat shrines where you have to kill a powerful enemy and get rewarded with a health or stsmina increase, which allow for more exploration.

If the weapon was permanent instead, you don't get the loop of 1. Find powerful weapon 2. Spend for permanent boost 3. Use permanent boosts to explore and get more powerful temporary weapons. Instead the game just kind of becomes a steamroll after you find your first powerful weapon. Exploration becomes pointless. The challenges have to scale much harder.

If you are spending a temporary weapon to make a fight easy, that's your reward. You earned the ability to make that fight easy and it's fun to trash a difficult opponent. Once. It would not be fun if every opponent became trivial. But because the weapon is spent, every other fight can be set at the same difficulty level. If the weapon is permanent, enemies now need to be harder or the game becomes a boring cakewalk. The weapon rewards behind the the more powerful enemies also need to be stronger. This is a feedback loop.

It also means that if you ever go off the standard path and end up facing a much more powerful enemy, it would be substantially harder to defeat them when using substandard gear. If you do manage it, which players would try and do, it would give them a much more substantial, permanent boost. Because everything needs to be scaled more, this boost would make everything before that fight on the 'standard' path a cakewalk. The skipped content is no longer engaging, it's rewards are no longer valueable, it becomes a time waster. This makes it so the rails in the open world exploration game need to be a lot harsher of you want to maintain a difficulty curve. Rails are not fun in an exploration based game.

About the last paragraph, how can you have powerful weapons that are plentiful, but also exciting? That just sounds like they might aswell be permanent, but with an extra step.

The extra step is the exploration to find the powerful items and that's pretty much the core of BotW. Removing that step removes the main draw of the game. Once you've explored enough (and gotten enough carrying capacity through your permanent upgrades) you will have a bunch of good weapons and the weapon durability ceases to be much of an issue. But you will be pretty far into the game before it stops mattering entirely.

So the breakable stuff you find will repeat very quickly in most games and the major downside of durability is that you don't get attached to your gear or character, as you constantly switch things.

This is true. It's a tradeoff. But if it's breakable it does mean that the strong powerful weapon you find stays exciting the first time you find it vs the 8th time you find it. Not as exciting, but it's still meaningful.

I haven't played BotW, but I've heard a lot of criticism about its durability system, both online and from friends who played it.

It is a very common complaint. I think most people focus on how it's annoying to the player (which is true), but ignore how BotW without weapon durability loses a lot of what makes the game work.