This is just one company. I worked for a big mobile games company, and their main complaint was how expensive where ads nowadays. They used to pump millions and get as many players as they wanted. Now you need to take a lot of care on how you spend your money, as the return of investment is not guaranteed if you pay too much.

If other companies follow suit, then we can talk about a more general issue. Maybe it is just that their campaigns were ineffective because were not good, or because their target users are not reached on digital ads.