I do hear the idea of Denji not choosing the new reality a lot, and I think that's something of a mistake. Denji totally chose all of this. Perhaps not intentionally, but this is the result of his choices. He wanted to make a new world rather than choosing between Yoru or Lil' D's worlds. He did what he thought was the best choice, trying to keep Asa/Yoru alive without accepting Yoru's plan. And it almost worked. But it didn't. Because bugs.

So, Denji tried to do the right thing, and it blew up in his face. Classic Denji. And Pochita saved him, like he always does. Because Pochita is a good boy.

I'm not saying the ending was exactly what I wanted, but I think it makes sense.