Mozilla Is Removing Tab Groups and Complete Themes From Firefox (venturebeat.com)
An anonymous reader writes: As part of Mozilla's "Go Faster" initiative for Firefox, the company is removing features that aren't used by many and require a lot of technical effort to continually improve. VentureBeat learned that the first two features to get the axe are tab groups and complete themes. Dave Camp, Firefox’s director of engineering, said, "Tab Groups was an experiment to help users deal with large numbers of tabs. Very few people chose to use it, so we are retiring it because the work required to maintain it is disproportionate to its popularity."
Firefox was suppose to be the fast and light browser. Then they kept on adding crap to it and made it one of the bulkier browsers out there. If you use more then 5 tabs open something is wrong and you should learn about bookmarks
If something is so important that you feel the need to post it on the internet... It probably isn't that important.