The comparison might not be equal in terms of how much they’re doing, but the Amiga was doing it on a single core CPU, so it could quite literally only do one thing at a time.

A modern OS running on a multi-core CPU has even less reason to hang - one of the cores should always be available to immediately switch context to handle UI events, even if the other cores are running a million processes. There’s no -technical- reason for it to hang, just poor programming.

Edit: Upvoted because despite disagreeing, your comment seems to have sparked a ton of discussion, and that's always great. :)