Their multiverses are different so their definition of a "Multiverse story" is different.

But since DC sure loves overusing it at the time, even in stuff where it shouldn't exist like Arkhamverse, I can't vote for them.

DC.

Marvel. DC has played with multiverses so much to the point that their shows barely resemble canon anymore.

They've both done good with the Multiverse, but since I'm more of a Marvel fan, I pick them.

Define multiverse story

Do stuff like What If and Elseworlds count or just crossovers?

You can count them if you like (I count them as multiverse stories too), but I’m mainly referring to the Crisis Events, Secret Wars, Spider-Verse, and The Multiverse saga.

DC started using it, so them.

Marvel