@soop My initial thought to your question was to mock, via this word substitution...

what does not-murdering peeps have over murdering peeps if you ignore the moral side of the choice? [insert your preferred act]

However to be serious, i'd offer these thoughts [only a sample]:

• ongoing existence of #Firefox helps forestall an otherwise browser-engine total monoculture
• container tabs
• cookie management
• #uBlockOrigin already works better in FF than chromium, & coming later this year, google will break uBO entirely.
• [though i sincerely wish this functionality was native within FF] chromium browsers have no equivalent to either #TreeStyleTab nor #Sidebery #AddOns, which provide [both, but especially the latter] the most sophisticated granular tabs management of all browsers

EDITED to add:

The existence of #Firefox means the existence of ​ forks, a marvellous example of which is ​ #Floorp. This still has all the benefits of vanilla  ​ [#albeit, #ESR in this case], but adds multiple excellent bells & whistles. I avail myself of many of these enhancements, but IMO THE most notable one is its Vivaldi-esque dedicated side-panel with configurable #WebPanels.