You can not pay to change Google reviews. Period. And the theories of "you dont know whats happening in all parts" is not true because I looked at detailed numbers myself and other than legal processes, everything was clearly visible.
If anything Google has a clearly different org and we often told very highly paying customers that even if they were paying us hundreds of millions a year that does not change our policies. One of the luxuries of being Google scale I guess.
Google gets a lot of (potentially justified) criticism on Hackernews but this conspiracy that Google lets businesses pay for reviews is plain stupid.