Eh, I'd say the biggest learning curve is updates and how they're generally password protected.

It's actually not straightforward to a new Linux user how to bypass entering your password every time there are updates, and with how often Linux updates, this can create headaches and confusion for new users.

Especially with coming from Windows and being used to Microsoft arbitrarily forcing updates in the background. They are confused because Microsoft gave them zero control, while Linux actually gives them full control, and that can be confusing when you're used to updates being forced on you in the background.

Linux expects you to be an adult and handle this shit, and does a lot less hand-holding for the casual user, and this can be overwhelming for some new users, because it's a lot of extra personal responsibility they formerly didn't have to think about. Some people just don't have the extra mental energy to dedicate to it all.