They're focused on soaking up big money first.

They'll optimize down the stack once they've sucked all the oxygen out of the room.

Little players won't be able to grow through the ceiling the giants create.

Why would they do that? Once they have their win-condition, there's no reason to innovate. Only to reduce the costs of existing solutions. I expect that unless voice becomes a parameter which drives competition and first-choice for adoption, it will never become a focus of the frontier orgs. Which is curious to me, as almost the opposite of how I'm reading your comment.