[WorldMaker]

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.

[Walf]

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.