I get and agree with focusing resources where you get the most payoff. But there is also something to be said for product differentiation. These two features definitely differentiate Firefox from Chrome and Safari, and do so in a useful way. There have been times that Tab Groups was the sole reason I stuck with Firefox. There have been times that the sole reason I did not move to Chrome was knowing I could never 100% personalize the GUI. Throw in the how Mozilla handled the DRM issue as well as Pocket and new tab sponsored websites fiasco and you begin to erode the privacy reasons for sticking with Firefox. Yes, Firefox must compete, must stay competitive, but if it becomes just another Chrome, there is no way they can compete with the resources Google can bring to the table. Firefox must compete on product differentiation or it will lose.

Another heavy tab group user. I can see that the panorama part with drag & drop support takes quite some work to maintain. The ordering of tabs in groups however should not be that much extra work and is the important bits. Simplifying the code instead of axing it would be appreciated, but guess that ain't never going to happen. Of course I also use classic theme restorer.

The Pale Moon browser comes up more and more so I suppose it is time to check it out.

edit: OK, installed and love it (at least so far). Migration was smooth. Ran the profile import app with both browsers shut down and have ALL of my old tab groups using the tab group extension that has to be installed separately (install after the import). Almost all of my important extensions that where about to stop working are just fine. It feels good to be home again.

Solution is simple, use Palemoon.

I've been using it for a few years now, its great.

It runs on all OS's, Windows, Linux, Android etc...