This is technically true, but this pretty much exactly illustrates my point. The SCM URL you've provided, you have to dig it up. It refers you to <https://man7.org/linux/man-pages/index.html>, which again, is a personal website of a member of the community. Then e.g. the fnctl(2) page comes from the 6.10 kernel release - AFAICT I can't browse the past releases or track HEAD. Compare with <https://man.openbsd.org> or <https://man.freebsd.org/cgi/man.cgi>, you can find both straight from the landing pages.

Meanwhile if you can't find man7.org (Google search results are only getting worse) and start browsing <https://docs.kernel.org>, it refers you to <https://www.kernel.org/doc/man-pages/> which refers you to <https://www.kernel.org/doc/man-pages/maintaining.html>, <https://www.kernel.org/doc/man-pages/missing_pages.html>, and Wikipedia - none of which seem to be relevant, can't tell because it's a wall of text rather than a man page browser.

Now imagine you have to fix a b0rked system that can't display its own man pages. You're now stuck with this mess.