since interest is gone and all. any benefits to using it?

if you don't want to accidentally buy something from shops, storing it in the bank is nice. there aren't any REs that take sP away any more though so you can keep all of your sP out without any risks

There isn't really a lot that can just take your sP without your input now. The tax events went, I don't think the one where Maleria steals sP is around any more either (not that she took much anyway).

It's probably handy for people on mobile devices. Since it can be easy to misclick (or mistap) on those, there could be situations where a mobile user might accidentally buy something expensive, if they had enough sP on hand to do it? If you use Subeta from a mobile device that's something you may want to consider.

Personally, I just like having somewhere to put all my sP away so it's not tempting me to spend it while I'm trying to save!

Goodness it's a way to put money away so you don't spend it! HEHE

like many have said, storing your sP to avoid spending it Maybe like you want to save for something but keep a bit to spend on quests and stuff...

I agree that in a way it might be pointless, but I dunno, I like to store my sP