In my experience, it's usually power users or basic users with very specific application requirements, who have trouble moving between operating systems. There's usually a FOSS alternative to those applications, but often requires reworking a workflow or upskilling more than they want to. But they're still basic users so it's more a speed bump than a road block.

So yeah, most people can switch to MacOS without an issue, and the vast majority of those can switch to a distro like Fedora or Ubuntu and quickly feel comfortable.

Power users get stuck in this situation where they've learned how to do advanced things in Windows, have things tweaked to support more complex and peculiar workflows, but often don't understand the actual concepts behind them. And even if they do understand the concepts, they still have to learn the alternatives in a new OS, and rebuild their workflows. Now, there's a lot more ability to learn behind the scenes about the why and how with Linux and BSD, so I'd argue they'd be better off to just suck it up and get started, and they'll be better off before long.