I don’t have numbers for how frequently it happens, but the need to use old releases happens on both OSes. If you’re using an architecture that Debian has since dropped support for, you have to stick on the old release. (They stopped supporting one of the MIPS variants recently.)
Debian also sometimes drops packages because they won’t build on the newer release and there’s no maintainer for the package. Now you need to stay on the old release (or port it to the new libraries yourself) if you wanna keep using it.
I don’t have numbers for how frequently it happens, but the need to use old releases happens on both OSes. If you’re using an architecture that Debian has since dropped support for, you have to stick on the old release. (They stopped supporting one of the MIPS variants recently.)
Debian also sometimes drops packages because they won’t build on the newer release and there’s no maintainer for the package. Now you need to stay on the old release (or port it to the new libraries yourself) if you wanna keep using it.