This sure is a thing normal consumers do. Installing a new launcher app.
That's just the top 4 and makes it over 115 millions installs. Facebook Messenger has 100-500mil installs. So I think it's safe to say that there is plenty of people that install launchers.
But anyway, I was pointing out that you don't require to reinstall the system to customize the system. In fact, you can make an android look like any of the other ones any time and without too much tech savvy-ness