Multi account containers + Temporary Containers [1] + I don't care about cookies [2] are an awesome combination I use, I have ~10 fixed containers and for almost everything it's a new container that lives as long as the tab is open.
Why do you need a container for almost everything? It's it for privacy reasons? If yes, what do containers offer which is not already provided by the total cookie protection feature?
[1] https://addons.mozilla.org/en-US/firefox/addon/temporary-con... [2] https://addons.mozilla.org/en-US/firefox/addon/i-dont-care-a...