‘And you are able to listen to the feeds for free rather than paying a monthly fee. No one is forcing anyone to become a feed provider.
I get both sides of this. This sort of, opaque and overt monetization of scanner feeds that are generally of a public service and nature -feels- wrong, somehow. I think most feed providers broadcast as sort of a community thing, generally using also free/open source software. But the radios and other equipment are entirely funded by the feeder.
It's one thing to serve banner or other text/image advertisements to listeners, and another perhaps to directly monetize the stream itself. I have to imagine that Broadcastify makes a pretty penny with that deal with Dataminr, and I'm pretty sure Dataminr won't be the only such deal either. Not to mention all the other income from other community supplied frequency data and associated deals with the scanner makers.
Now, on the other hand, running such a site does incur costs. Storage, distribution and bandwidth isn't free. But, in 2022, these costs have plummeted compared to a decade ago. Media can be transcoded in the cloud in real time, for very little cost. Websites no longer require bare metal hardware. Kubernetes, docker, and the proliferation of serverless functions like AWS Lambda mean that when properly architected such a site may incur very little base cost, mainly only being charged when active listeners are present.
So, I guess it's just up to the feed providers to decide, if they feel like the monetization of their work product is wanted or a fair trade for a $30/annual benefit. It would help make that decision if we could know the full picture, but I suppose we won't get that.
Just a note, there are free alternatives. OpenMhz.com provides Calls type functionality and is community built and supported. The server behind OpenMhz is called TrunkServer and is also open-source and available for download too.