Can jubilance ever be useful? does it get high enough to actually help with exp? what is the point of it if not?

It depends if you want to sit there in town for a long time.
I personally don't find it useful, but it could always be something to play around with.

Here is the max per tier.

it really no use. If you get your gear with max jubilance and walk away from your computer, you will eventually become disconnected. You would be better off killing 1 mob walking away and repeating that process than to just sit with jubilance on

this