The Facebook Container is very usable for non power users so long as they're already uncomfortable enough with the all-consuming nature of Facebook to not use Login with Facebook type features (which can't work from a container by definition)

I'm not going to get my mother to use containers to keep her banking separate from her knitted craft forums, the same way I'm not going to get her to use a password manager, but I can install the Facebook Container and buy her a book to write passwords in so she uses more than two different ones.