I recently discovered STG, and I cannot stress enough how great it is! It takes a minute to set up with colors and group names. But, oh my, how great it is to have my Spotify, Lastfm, and Bandcamp in a Music group, all my work stuff in a Work group, all my general stuff like Facebook, Lemmy, and email in a Home group, shopping sites in a Shopping tab, and so on. Being able to toggle between them is so useful.
Firefox: uBlock Origin, Bitwarden, Simple Tab Groups, New Tab Suspender, SponsorBlock for YouTube.