At least my coworker's former 16GB MBP (until he got a new one now) basically halted when the emulators were running, and he had to close lots of programs. Not strictly appdev, though, so he was then running and developing our backends locally, running some other needed services in docker, and then working on the android and ios app at the same time to match and test the changes in the backend. So basically all of my examples above, but at the same time.

So not strictly necessary, but when you're used to it going back to having to work around the limitations is burdensome. People not having lots of ram seldom complain, but they don't know how much time they're wasting on an inefficient workflow.