This is (or was, before I switched to Vivaldi) the killer feature of Firefox containers for me. I could banish certain tracking-heavy sites to their own containers so that they could only track where I've been on their own properties and not across the whole web. (Without having to remember to switch to their containers beforehand.) So I guess if I go back to Firefox, I'll still have to use the extension.
And maybe I'm misremembering, but I thought that containers did more than just separate the cookie jars? I really like using Vivaldi/Chrome's separate profiles because then I can have separate extensions/settings/polices/etc for each one. Some sites don't get along with certain extensions.
For me, this is almost an anti-feature. I still use it for a few sites, but the real killer feature of containers is that it becomes a breeze to use the same service with different accounts & identities, without logging in and out, and no shared state. Pinning a site to a container breaks that.
They are definitely orthogonal use cases. I find I prefer Profiles for different accounts/identities more than Containers (including profiles being very different windows of Firefox reducing confusion of which identity I'm looking at). Containers I like using for those hard privacy walls of pinned sites to avoid more "personalized" ads. But the flexibility exists to mix and match and use Containers and Profiles for either/both use cases. I don't think there's a "wrong way" to use them, just your personal preferred way.
Profiles for separation is good for large differences like work and personal life, but I find the lack of shared history, bookmarks, and add-ons to be a pain. Running them simultaneously is annoying because only one profile is considered your default browser, which can receive external links, e.g. from your email client.
There are some good add-ons to pin bookmarks to specific containers, which helps.
> use the same service with different accounts & identities
Last week, I needed to do Google Takeout on a doz different user accounts (hours between request and availability). In a few seconds, I had a doz temp containers to keep the sessions alive and isolated, until the downloads showed up.
This is (or was, before I switched to Vivaldi) the killer feature of Firefox containers for me. I could banish certain tracking-heavy sites to their own containers so that they could only track where I've been on their own properties and not across the whole web. (Without having to remember to switch to their containers beforehand.) So I guess if I go back to Firefox, I'll still have to use the extension.
And maybe I'm misremembering, but I thought that containers did more than just separate the cookie jars? I really like using Vivaldi/Chrome's separate profiles because then I can have separate extensions/settings/polices/etc for each one. Some sites don't get along with certain extensions.