It depends on why you are using Container Tabs.

"Total Cookie Protection" isolates third party cookies on a site-by-site basis. So for example, if you load pages on 3 different sites and each has the Facebook like button, Facebook isn't able to easily link those together because the FB cookies won't match between the 3 sites.

But if you want to log into two different accounts on the same site at the same time, you still need to open one of them in a container because you need to have different first party cookies.

Does that make sense?

Yes thank you