They're not as strong a separation. That said if they work for your usecase then yes they're lower friction by the same virtue. It is very loosely like containers being cheaper than VMs at the expense of some isolation.
Chrome profiles, for example, isolates browser extensions, bookmarks, browser settings, and saved passwords. I haven't used Firefox containers yet but, based on the docs and demo I watched, it doesn't look like it has that level of isolation.
Firefox history is shared among all container tabs. While some of my usage is automatically governed, not all is, hence why I moved to profiles for certain needs for separation