Hickman turned it around by letting namor live and giving all multiverse saving credit to reed?
I have to agree with SI here. Namor lived because the editors decided that the Squadron Supreme writer gets his wish to kill him.
But BP may have not been THE key player, he still was an essential player in the end. Without him, Reed wouldn't have won. (And given that this series was changed into the FF swan song, Reed had to be given the key ending role.) And technically speaking, BP pulled it off, restored the city, saved the lives of the kids, sent them into space, and every indication was he undid all the damage. Coates, at least to me, decided to undo it and make it a partial restoration and not a complete one.
You may not like how he got there, and BP may not have shined or was given his best show, (especially since the whole story was what happens when heroes cannot win), but in the end, he was just as important to victory as Reed was.