I've taken advantage of the customisation features of the Vivaldi browser, by doing the following:
- Removing the close buttons from browser tabs,
- Learning the keyboard shortcuts for cycling through tabs,
- Making new keyboard mappings for tab management,
- Shift + Cmd + W to close all other tabs,
- Ctrl + Cmd + W to close all tabs to the left of current one,
- Opt + Cmd + W to close all tabs to the right of current one.
I should note that I don't keep that many tabs open at any one time, usually only the ones I need to perform whatever task I'm currently doing. Anything that I may want to refer back to gets sent to DEVONthink for safekeeping.