That's a personal opinion, not a prediction. FM still has 98% of the 'radio'-based music listening. The demise of FM was predicted when Sirius and XM were launched back in the 90's for very similar reasons. It's been over twenty years, and the predictions haven't happened yet.
Commercial radio relies on advertising. That hasn't, nor will it change in 2021. The difference will gradually become that station groups like Cumulus and iHeart will continue to redirect expenses to content creation and quality of programming, from local studios, offices, and elimination of back-office costs. The expensive quality talent and programming will be featured nationwide through market -by-market transmission sites and steaming to Alexa and Google devices.
As David mentioned, success isn't directly attributed to how much money one spends. It's where the resources are being spent that matters. If local studios, offices, and their associated personnel expenses are eliminated, there are more resources to be spent on research and content development.