I'm a containers early adopter and have 38 containers (just counted them) that are highly configured. There are many extensions that not only honor containers but allow for detailed customization.
That said, even just the "built-in" Multi-Account Containers will allow you to pin a domain to a particular container - i.e. amazon.com will always open in a Shopping container, wellsfargo.com always in Banking, slack, github, netlify always in Work, twitter only in Social Media, Gmail and YouTube in Google, etc.
Containers themselves are effectively just a label and a (limited) privacy sandbox. So far I have experienced no performance hit nor other issues so I create new Containers at will. Thus if you have 6 gmail accounts you can create Google1, Google2, and stay logged into all of them all of the time.
Additionally, I use the Cookie Auto Delete extension to only persist specific cookies to specific containers while all other cookies are wiped. I can maintain my YouTube subscriptions in a container that stays logged in my primary gmail account while being able to also watch other random videos in my Random container without polluting my real account history.
For work I have about 6 different accounts that I can be actively logged-in with; each tab is a different user with an entirely different role (for testing) and all can exist side-by-side.
As other have mentioned, you can always right click on any link from any container and open that link in a different container.
For me there is no going back to "standard" browsing. I can remain independently logged in to whatever I choose and feel confident those cookies are segregated from any other browsing activity. (obviously my IP is the same and some forms of fingerprinting surely still manage to track me in some manner)
Recently I added the Containerise extension which allows for even greater granularity with the always-open-in-a-container feautre: it allows for subdomain & even regex-based url rules. So, for example, console.aws.amazon.com can open in an AWS container (logged in my work email) while amazon.com can open my Shopping container (logged in with my personal email).
TLDR - containers plus extensions are extremely flexible and powerful