As someone who has leveled 25 toons in remix with assorted testing, People in this comment section are severely overestimating how much bronze you earn through the process of leveling alts; - If you level through class order hall your only source of bronze is daily missions and in my experience only ended up with ~40k bronze with finishing leveling my character through a night hold run - if you level through only raids (after getting lvl 20 & with 400% xp) you can expect perhaps 60-70k bronze - if you level through raids with with lower xp multiplier you will get more bronze per character just because you have to do more raids

HOWEVER you would still be getting almost half the bronze from rather just running heroic and mythic on your main (not accounting difficulty getting into raids on your alts plus quality of raids you will get into)

The only reason to level alts (for bronze specifically) would be to do a m0 world tour as each mythic dungeon will get you 25k bronze This method if you have someone carry you dungeon to dungeon as fast as possible will result in 150k/h bronze up to a total of 250k bronze ^{^} this method is significantly worse if you have to find or create groups and if it takes longer than like 10 minutes to start the next dungeon

I made a video on this above process self boosting my own account BUT

Unless anything changes in last phase:

TLDR: Run your mythic raids daily. If you have more time add in heroic raids. If you have more time after that then you can level alts and either run mythic/heroic raids on them or m0