Yes, while Apollo is generally a free app, it has a premium subscription for users, providing advanced features like push notifications and other stuff. Since the app developers have to run their own backend to make those features work, users have to pay a small fee (what is totally OK for me since it is such a great app and I liked to support the developer this way).

You are right that this just solves a small part of the problem. If the numbers I have seen are correct, the API calls from all those mobile apps just make up a small number from the overall. A huge issue seem to be all those search engines and AI dudes feeding their stuff with data from Reddit (🫣 why would someone want to do this...). For those, I think it is still fair to let them pay per API request. So they could just give regular users a large amount of API request and force commercial users who want to scrape content with their bots to have an enterprise business plan and pay per API usage.