abcdw, 
One of the most useful extensions for Firefox (actually LibreWolf) is Sidebery. Finally I can decrease a mess of tabs and make them structured.
There are a lot of features, but most useful are:
- Rules for automatically moving tabs into "panels" (a grouping mechanism similiar to workspaces).
- Foldeable tree view.
- Rules for openning tabs in specific containers (combines well with container proxy and multi-account).
- Integration with bookmarks.
