Others have mentioned power - you may want to do some math on drive cost vs power consumption. There’ll be a drive size point that is worth the cost because you’ll use fewer drives which consume less power than more drives.

Having built a number of systems, I’m a LOT more conscious of power draw today for things that will run 24/7. Like my ancient NAS draws about 15 watts at idle with 5 drives (It will spin down drives).

More drives will always mean more power, so maybe fewer but larger drives makes sense. You may pay more up front, but monthly power costs never go away.