When you change function signature it doesn't compile until you fix all the call sites. Maybe after you see all the broken call sites you think that's too much work maybe there is some other way to do what I want.

When you change anything about an endpoint, it compiles just fine no matter what clients there are or what they are doing. You proceed with the change without worry. Yes, you can have some self-discipline to also generate the open api documents, generate the clients and then check all clients but self-discipline like that is not reliable.

So while tooling can help it's still not the same thing.