I believe that the more money invested into marketing, will take away more money from the players. The players must pay in some way to sponsor those teams and I hope this is not done by decreasing the RTP for the games that are played.
Also, that money could have been spend on improving the UK casino. (Have you seen the low quality of the UK casino) ?
If they thought long term they would make more money by decreasing the RTP, they would decrease the RTP. Their marketing strategy has nothing to do with this.
The money they spend in advertising has nothing to do with the RTP or bonus amount.
You are a revenue generator for Stake, not an investor.