I'm afraid I'm a bit of a one-issue voter when it comes to web browser, and the reason that I haven't switched to Firefox from Chrome (even though ideologically I want to) is this workflow that I use for clicking links in other apps. I open an incognito/private browser window in the foreground, then click the link in the other application. In Chrome, this opens the link in the incognito window. In Firefox, this opens the link in a normal browser window. In order to open the link in a private browser window, I have to manually copy paste the link between applications into the private window. I follow this workflow when the link is some site that I don't generally visit, or don't recognize, and hence don't want to access any cookies associated with my regular browser window, and importantly, also don't want to show up in my browsing history.
I recall there being an issue on Mozilla's bug tracker where someone brought this up and it was closed as a wontfix. Unless there is something about Firefox's container system that obviates my workflow, I'm still reluctantly sticking with Chrome.
Depending on the apps you're clicking links on you might be able to drag the link onto the incognito window. Still more annoying that it default opening incognito but nicer than copy/pasta.
I still haven’t switched from chrome because of the superior multi-user switching and the ability to have different proxies on different user accounts.
I recall there being an issue on Mozilla's bug tracker where someone brought this up and it was closed as a wontfix. Unless there is something about Firefox's container system that obviates my workflow, I'm still reluctantly sticking with Chrome.