Containers feel like a much more useful feature to me than profiles - I don't wanna open a new window for each website that I want to isolate from my main session, but with containers, it's trivial.
I mostly agree, and I personally just use containers (and heavily!) However, that has not been the case for my spouse. Profiles are important to her in two scenarios:
1. The primary website she uses for grad school (canvas) REQUIRES third party cookies to be enabled for it to work. Containers cannot have different settings here, but profiles can. So she can have a School profile that enables 3rd party cookies and she just uses this profile for Canvas.
2. She likes to keep ALL of her work stuff separate and not have that sync to her personal mobile. So she has Personal Profile (with containers) and a Work Profile (also with containers). The two profiles are themed differently, so it makes it very clear if she is in her "work" browser or "personal" browser.
Firefox's profile management has been a struggle for her (I found creating different application icons for each profile worked best), and I am very excited about the new profile manager!
