That said, containers are a handy tool for people who want to access multiple accounts without the trouble of setting up individual profiles. Keep in mind, if you're only trying to access a personal and work Google account you probably don't want to spend time setting up a separate profile for each then keeping the settings synchronized.
Starting a profile is difficult, and also switching between windows, since the OS sees profiles as different apps. It's probably not hard to fix, but Mozilla has had other priorities.
I don't know why they don't add this somewhere in the menus and I don't know why you can't bookmark about:profiles, but this works well for me as it is.
Add-on: https://addons.mozilla.org/en-US/firefox/addon/profile-switc...
Source: https://github.com/null-dev/firefox-profile-switcher
- Junction (Linux browser picker): https://github.com/sonnyp/Junction
- Finicky (macOS browser rule setter): https://github.com/johnste/finicky and Browserosaurus (macOS browser picker): https://github.com/will-stone/browserosaurus
- Hurl (Windows browser picker): https://github.com/U-C-S/Hurl
You can create shortcuts (or shell scripts) by hand with --no-remote -p ProfileName to auto-open specific sites in specific profiles. It's certainly less convenient than PWA installs, but is an old tool with all sorts of old ways to automate it.
Multi-account Container is far easier than all that though and does reduce the number of windows to manage in your OS taskbars. Obviously you need to be careful with which extensions you install that they are safe for every container you want to use, but that's a given and a good idea in general no matter how many profiles you use: keep extensions to the bare minimum you are comfortable with. Vet their permissions manifests and keep additional permissions you grant them to a minimum.
This matters when you can't 100% trust your browser session, or the installed extensions. Did you ever load https://my.1password.com in your browser? How do you feel about it? Do you trust your installed extensions to not take a peak? I don't.
Chrome solves this elegantly via profiles. Even more, you can install websites as “apps”, with a shortcut that gets indexed by the OS, and Chrome remembers the profile. I simply type “1Password Online” or “Banking” and my Chromium opens a new window in my “Private” profile that has no extensions installed. Firefox dropped the ball on both PWA shortcuts, and on profiles.
Even for using multiple accounts, I feel like Chromium profiles are a better solution.
For example, my workplace has very strict security requirements, and when looking at company documents it's not cool to provide access to extensions like LanguageTool or Grammarly. I'd be in trouble. And Chromium always had finer grained permissions for extensions, like activating or deactivating them per website.