What I still find fascinating about the Apple machines of the OldWorld era is not how small the on-disk system was but how much they tried to stick in ROM. My Centris 660AV had QuickTime burnt into the ROM chip. Of course, before anyone used the machine there was a software update to QuickTime so there was no point.
We also had a Mac Classic that has a whole system disk in ROM that you could boot from if you held down a secret key combo.
Later on when SCSI hard drives became more common there was more features to the Mac System.
System 1.0 was like a proof of concept. It just worked and you were lucky if you didn't get a system bomb error message.
The old Macintosh laptops had to power them on to show airport security they weren't a bomb, and hope the system bomb error message didn't come up and confuse the security guards.