That's not too surprising. Early MacOS didn't provide much more than MS-DOS under the hood (non-hierarchical file system, manual multitasking), and the graphics were all 1bpp.
I didn't realise it didn't have a proper file system. Games were more glorified as far as user interface was concerned, e.g. the 2000 planet system with 3D graphics of the BBC Micro's Elite, running on an 8 bit 6502 machine with 32K usable RAM.
You can see the Mac OS as an expensive 'game' with the objective to write a letter, running on dedicated hardware.