Chrome let you run multiple instances with as different users. I haven't seen this in any of the other browsers except via command line arguments. If this isn't a feature on the table, I for one ditch chrome for Vivaldi. I do a lot of web design and like to create user account for each client and work in a separate browser for each client. That way, when I'm done I can hand over the username and password and all my bookmarks etc. are available to them.