True. And that would yield 2% compared to 3%, probably mostly covered by the base stat difference. However, you're then stuck with an Accessory you can never again enhance - not without an absolutely ridiculous Gem cost. Not that you need to since the performance is already roughly the same, but... whose autism will allow a non-max level item?24% is absolutely insanely huge, though. We're talking P2W Eidolon level of increase.
... of course, not only that Belial and friends are team-wide, but you're also basically never going to find even a single triple Atk+ SSR. Much less three. Even less ones for the whole team. Not that you'd even want to use them over Affliction+ Accessories on your debuffers.
But still, let's not call 24% as "only." You put that on the carry of your team - best case SSR Cybele - and your team is a now a monster.