MacOS's current Finder dates from 2001. Earlier versions of "Finder" were a completely different piece of software - different code, different interface, different UI metaphor. File manager software predating it:
Windows Explorer
GNOME/Nautilus
KDE/Konqueror
X11/xfm (X File Manager)
sundry proprietary Unix workstations
All of the above interfaces share the same interface lineage as Mac OS, lying as they all do downstream of Xerox PARC. And all have converged on the same interface principles - visible path, a button to ascend to the parent directory, etc.Everyone who comes to Finder from anywhere else complains. Finder is weird for the sake of being weird.
Arguably it dates from NeXTSTEP so 1989.
The PARC interface (by which I guess you mean the Xerox Star) had significant differences, and I think would confuse any modern computer user far worse than the Finder. The Lisa was closer to the Star but the Mac used a simplified model that just equated files to icons.
Source: I lived through this process and used all of these for actual work at some point. The Finder’s influence on GUI file management was rather like the iPhone’s influence on phone management.
Why would they ignore all the lessons learned between 1984 and 2001?
That's the reason why most people complain about Finder today.