Although the Amiga Workbench has pre-emptive multi-tasking it not only has but encourages use of a backdoor to switch off the pre-emption. As a result you don't gain as much as you might hope over systems with co-operative multi-tasking like Windows 3.x - Apps A, B and C may be getting along just fine, but if App D is selfish enough they're all screwed anyway. Together with lack of memory protection (for hardware cost reasons initially) this means Amigans don't end up making as much use of the multi tasking as you'd think - if I run A, B, C and D but then the system crashes, who do I blame?

That backdoor is still there and causing problems in 2022. You can buy a 64-bit multi-core "modern" Amiga but it is still running an OS with a stop-the-world backdoor to switch off pre-emption, and so it only ends up using a single core in 32-bit mode. Or you could put Linux on it.