Maybe not, but even ~1% is still an unacceptable slowdown. It would take
about a year for the compiler to catch up.
(Un)acceptable for whom? And why would it be unacceptable?
You just said compilers will make up for it quickly, not to mention
hardware continuously getting faster too...
I haven't seen any convincing arguments as to why such a small
drop would be the end of the world.
And I don't think Fedora is or should be used in high-speed trading or similar
environments where every microsecond matters.