> No; in fact it's perfectly reasonable,

And this is how I once ended spending a Friday evening in a frantic hurry because a dependency decided to drop support for "old" language versions (that is, all except the two newest ones) in its patch-version level update. And by "drop support" I mean "explicitly forbid from building with language versions less than this one".

> The entire reason we have version number schemes like this is so that we can improve our code while also advertising reasonable expectations about compatibility.

Except, of course, some library authors deliberately break semver because they just hate it, see e.g. quote in [0], slightly down the page.

[0] https://dmytro.sh/blog/on-breaking-changes-in-transitive-dep...