I disabled SIP, but directory /usr/bin is write protected anyway. I have cocoapods installed to /usr/bin since old version of OS. And now I can't uninstall anything from that system directory.
This, I'm presuming, is by design. With Catalina, a boot drive now consists of a read-only System volume, and a separate Data volume. While this is semi-invisible, you can see it in Disk Utility. I doubt that playing with SIP will affect that. You may need to do a clean installation to get rid of such cruft you no longer want.
I undestand that clean instalation heals everything. But it's very strange for me if new OS requires to delete all previos and execute clean instalation.
Indeed, it is strange (or at least new.) But this new partitioning, in which system and data reside on distinct APFS volumes--and the system volume, again, is read-only by design, is unprecedented.
