Essentially, the antagonist of Xenoverse 1, Demigra, was capable of destroying ALL time and space and rewriting it in his image. The difference is that unlike in canon Dragon Ball, there are an infinite number of timelines in the Xenoverse/Heroes continuity, which would already put Demigra’s feat vastly above canon Zen-oh’s best feat (annihilating an entire timeline). At the time it took Xenoverse SSJ3 Goku post-BoG (but pre-RoF) and the protagonist to defeat Demigra.
Later in continuity, Demigra unlocks a new transformation that makes him even more powerful, but as Xeno Goku has grown a lot stronger, he was able to more or less stalemate Demigra in his base form, and defeat him in Super Saiyan.
So more or less, Base Xeno/Heroes Goku has better feats/scaling than canon Zen-Oh. Heroes SSJB Goku is about on par with heroes SSJ4 Goku, and base Cumber matches/overpowers SSJB KK Vegito.
Gogeta legitimately dies instantly.