No big distro supports it and I can only think of one that still does (Adelie). Modern web browsers won't easily compile for it, probably other packages. And soon support for GPUs like the ATI Rage commonly used in 1998-2001ish era Macs will be removed from the kernel.
Isn't there an unofficial Debian port? Stuff can be added back to the kernel if people commit to maintain it and keep it in line with the evolving code base.
We still do ppc32 kernel build+boot tests in CI. Wonder if we should consider spinning those down...
MintPPC is quite good (or was last time I tried it):