My last time in Thailand 2013 ish, had a friend who owned a business. Had to pay the local police 10k baht a month "protection" money. Then his business got more popular and police from another (precinct) came by and demanded money also. Think he was paying close to 20k baht a month... To the RTP, just to stay in business. And I believe operate out of normal times also.
Point is, that's one case from 10 years ago. And I clearly remember learning about "brown envelopes" and "tea money" back then.
Also I just got my visa extension... Not just the RTP when it comes to the envelopes.