That seems a lot of money, but not too much to say the truth, when we compare to the total sum of money 'Procter & Gamble' spent in advertisement during an one year time period, totalizing 8.1$ billion dollars. That is just one company spending more than every iGaming/gambling services you mentioned.

Leading advertisers worldwide in 2021, by ad spending

Now imagine how much income these companies must make to give themselves the right to invest so many billions of dollars in marketing. Our daily financial reality is so distant from the world big techs' entrepreneurs one, that even their average numbers are already enough to surprise us, while the top numbers are so high, that most of us don't have any representation of that in our minds. It's like they didn't exist in our universe...