That's very strange. Probably centos is stripping "docfiles" from the installation (maybe a "container-optimized" install?). You can see which files are marked as documentation with "rpm -qd findutils". On my rhel 7, the man page is packaged along with findutils and I do see it.
Re:OpenBSD: Why and How (2016)
by somerandomqaguy on Wednesday November 13, 2019 @11:41AM
(#21526087)
I'm seeing the man pages for find on my Centos 7.7 boxes. Are you looking at a docker container or a cloud image?
Semi-recent Centos7:
$ which find
/usr/bin/find
$ rpm -q --whatprovides '/usr/bin/find'
findutils-4.5.11-6.el7.x86_64
$ man find
No manual entry for find
$ more /etc/redhat-release
CentOS Linux release 7.7.1908 (Core)
So it claims to have the findutils rpm installed, which comes with manpages (especially since there is no find-man rpm) but I didn't get them for reasons. You just don't get that kind of experience on BSDs unless you very deliberately unmark manpages for installations. (which could be some kind of usecase, sure)