Waterfox G5, because it's literally just modern Firefox ESR but with the ability to install legacy add-ons re-enabled.
I use this to make my own personal CSS themes and JS add-ons (as well as use existing ones like in the link above) and manage them in a way that's more elegant and streamlined than userChrome.
Anecdotally, this is a position I've seen held more often by young people than by boomers. Not sure what the statistics are exactly, but regardless it would be nice to see a cultural shift away from alcohol.