> Fair-ish point, if a bit cheeky. But threads can be still threads, i.e. in the same address space, but without actually having shared state between them. And then they're still threads, not processes.

If they don’t share state implicitly, then by all relevant features they are processes. That they share an address space is not really relevant except as an opportunity for optimisation. See BEAM.

Hell, older consumer OS used to not have memory isolation, even after multitasking was introduced.