(On Windows anyway, don't know if different on Linux)
Just wanted to share that as a user of both Firefox and Chrome, it's one thing that makes me hate switching to Firefox. I often need to use two different profiles and the way Firefox does it sucks.
With Chrome I've got two shortcuts (that Chrome creates by activating an option) pinned to my taskbar that look distinct from one another and the instances that I open are combined under their respective profile shortcuts.
With Firefox I need to manually create two shortcuts, assign two distinct icons to differentiate them, change some properties so they open the right profile, pin them and because they're "regular shortcuts" instead of the default Firefox launcher shortcut, when I open the program I end up with a third Firefox icon in my taskbar (it does not open under the shortcut I used, it acts as if I clicked a shortcut on my desktop) where all instances get merged together no matter which profile they're associated with.
I imagine Chrome prioritized this feature because it's valuable for them to clearly distinguish different users (and because they can).
Given the limited popularity of the feature Firefox sounds good enough. I used to use two distinct installation and had satisfying results for my use case.
But Firefox already has profiles, I'm just saying that they just need to go over step further and allow us to create "real" shortcuts for each profile instead of forcing us to use a roundabout way to achieve an unsatisfying result.