Firefox

I'm using the Firefox Multi-Account Containers Addon to reduce Google/Amazon and others following me around on the internet.

It's also useful to switch between multiple accounts on the same site.

I'm a little fed up with that addon though, mainly because it's impossible to set up a default container for a specific site (main account) while still being able to open that site in another container (alt account) when necessary.

I read something about how Firefox containerizes each tab automatically without any addon so that the Muli-Account Containers are redundant? Is there any truth to this?

How do you handle multiple accounts on websites?

Basically looking to get rid of the Multi-Account Container addon.