> MacOS is basically unusable without logging into an Apple account

It depends if you mean the OS + cloud services + app store, or just having an OS to run programs. The former definitely needs the Apple ID, but the latter doesn't. When I first switched back to macOS I refused any Apple ID linkage during OOBE and it never asked again. I just used Nextcloud, Firefox, LibreOffice and FOSS utilities, everything worked.

Later I did connect it after researching Apple's privacy policies, encryption methods and on-device processing - afaik I'm getting the cloud goodness without Apple selling my data, and that was enough to sway me.