Containers are useful for separating "who I am to my providers." As far as Facebook is concerned, I am a Facebook user, but I don't use Amazon or Google. But Amazon thinks I'm an Amazon user that doesn't use Facebook or Google. You can accomplish this with profiles, but in Chrome (last I checked) that meant multiple windows, rather than just sites being displayed in tabs that indicate the container in use. So for that purpose, I believe containers are more useful.
(I also think Firefox should step up their profile game, because when my spouse and I alternate using a computer we share, it's inconvenient for me to close all her Firefox windows so I can open my profile!)