My hill is that whatever os you’re already familiar with, will always feel easiest. Everything that does something differently, will feel more difficult no matter which one is easier for someone who has no prior experience of either one.
I could tell you how painfull it was when I had to start using windows at work knowing pretty much only Linux beforehand, but that too would be just an useless anecdote.
I think the most effective approach to increasing Linux userbase would be to adopt the same strategy Microsoft is using: Push for using Linux in schools, so that it would be the familiar OS for new generations.
Switching back to Windows shouldn’t be an issue. Going in the first time is horrible. Whatever the many papercuts of a given os are, you won’t even notice them if you’re used to working around them.
As for the kids, they’ll get their first experience sooner or later, depending on The curriculum of your country. But he same principle applies no matter wether it happens in university or elementary school.