They bring up good points here:
https://searchengineland.com/should-we-be-paying-for-google-my-business-features-316602
Google has a serious problem with GMB spam. Although processes are in place to technically prevent it, they are
utterly toothless, leading to a situation that’s just getting worse and worse and leading to
a lot of faith lost in the legitimacy of Google Local listings.
Now take a look at some of those features in the survey list: Verified reviews, Google Guarantee, Background check, Verified licenses and Verified bookings.
That’s a lot of features designed to boost trust in business listings. In fact, features centered around trust and verification make up 25% of all those listed, and knowing the current state of Google My Business, it’s not hard to see why.
Even the most cynical of those wondering what steps Google might take to tackle spam would likely be hard-pressed to say “monetize it,” but that looks suspiciously like what’s going on with these trust features, at least if Google charges for them.
Yelp has already gone down this route with its “Verified” badge and, depending on who you listen to, the veracity of these badges is either bulletproof or up for debate. What’s not really up for debate is that
Yelp is monetizing a lack of trust in certain business types by charging to vouch for them.
And so it is with Google, though with deeper consequences. Faced with a spam problem getting out of control, they seem to be charging businesses to highlight their legitimacy and trustworthiness rather than investing in better spam removal technology.