But okay, I'll bite. How is fly.io not the Web?
Well, fly.io is not the Web, but also it’s not the point
The closest I can get to what your questions is to say, it’s under the control of a for-profit company financing itself with shareholders who want to see profits? That’s true of many companies, the sentiment in the GP comments applies to the general pattern of becoming enshittified after a large investment / sale, not specifically fly.io
And more generally: people do things for money. Companies wanting a profit is not a bad thing. That urge can go wrong, but that risk is mitigated, in fly.io's case better than most, by the lack of lock-in technology choices.
For example, if you want to, for some insane reason, build an application that uses Microsoft's CosmosDB, then your data is stuck in Azure forever. Fly.io doesn't have that problem, as they use things you can run elsewhere.
So: what is the problem, as pertaining to the topic of this comment page: fly.io?
Don’t build your app on someone else’s platform. Whether it’s Twitter and Periscope, or Apple vs mamy developers (https://www.washingtonpost.com/technology/2019/09/05/how-app...) … build on a permissionless platform that isn’t owned by any gatekeepers. Like the Web. Or Ethereum. Or Polygon.
Utility tokens and micropayments via trustlines are exactly done for that purpose.