You seem to have misunderstood. We're not pointing out that "semver is semver", we're pointing out that semver as defined with respect to compilers, which is to say, the ability of existing code to run with a new version of the compiler, and what you "perceive to be a limitation in semver" are fundamentally in tension.

The only non-perf changes that would be allowed as non-breaking changes if we addressed what you perceive to be limitations in semver are precisely those changes which would be breaking in semver-as-it-exists, and those permitted in semver-as-it-exists are precisely those which you perceive as limitations.

Happy to discuss semver, but fundamentally the thing here is that what would address your perceived limitations is... the literal opposite of semver. Which is fine! But something not being its literal exact opposite isn't exactly a flaw in the thing itself; you simply want something else entirely.