It's kind of insane that the Amiga didn't do better, given it had much better graphics and sound than the PC at the time. It effectively had some simple accelerated 2D graphics. It feels like a wasted opportunity.
The later Amigas (3000 for sure, don’t remember about 2000) did have the memory protection, used e.g. by Enforcer.
It definitely helped, but it did not prevent processes from writing all over each other like on a modern operating system.
It was, hands down, the best hardware/software combo out there. If I remember the article correctly, the Amiga failed for other reasons. Bad marketing, bad Commodore management decisions, etc.
they didn't understand magazine article sold machines. so simple.