the execution came down to a dull line of endless monologues and tensionless battles
Interestingly, this is exactly the same as the Fate franchise. The Fate franchise has the source material fanbase to keep it profitable, as well as ufotable which have shiny lighting. Ufotable's animation isn't extraordinary and the art style isn't impressive. The shininess is what draws peoples' eyes to it and Re:Creators wasn't shiny.
Maybe the soundtrack helped it too.