Really, it seems to come down to the quality of the applications you're using, as none of the OSes really have any way to protect themselves from an ill-behaved application.
That´s the core of the problem. In the early days, many programmers thought they could just write software for the Amiga the same way they were used to on other platforms. Not only did they waste resources, but they didn´t properly clean up after themselves and ended up trashing system data structures.
the gradual decay of a poorly-manufactured floppy can make software act a lot more unstable than it really is.
Never happened to me. Most of my old disks are still working.
Really, crazily enough, if you want stability in older computers, you just can't beat DOS.
You can. DOS is a stability nightmare! I don´t know how you can forget that installing extra memory would break your software installations. Mice would stop working because of programms that reconfigured the COM-Port. One program would install something in your config.sys or autoexec.bat and the system would refuse to start at all. It took people days to make a new GFX-Card work with their games. And if you didn´t have a Souindblaster, but a compatible card, you were likely to have no sound in 30% of the games. Drivers would hang themselves midway in a program and there would be no error message at all.
Don´t kid yourself. The DOS you are seeing nowadays is a standardized virtual machine. The real DOS was very different in stability.