I don’t understand how it works in the US for cellular data.
In France, you subscribe to a package with a mobile company and in this package you pay for a given amount of cellular data per month. For instance, in the package that I chose, I have 100 GB of monthly cellular data. If I use more, I pay for it.
What are these “Verizon hotspots” and “regular unlimited cellular data” that you have in the US?
In France, the cellular data and what you call hotspots are included in the same package to which you subscribe. It doesn’t matter for the mobile company if the data was used by the phone itself or by a computer that used the phone’s cellular connection to the internet.
Why the stream of Apple Music is not included in the cellular data that you consume?
In France, the mobile companies don’t care if the cellular data comes from Apple, Netflix or whatever…
And do you think that Apple has a special deal with the mobile companies, that Tidal or Qobuz do not have, to let it stream data beyond the user’s package?
I understood now. This is because you stream Apple Music with an app on your phone, and not on your computer through a hotspot.
I don’t understand why Roon and Audirvana don’t release a phone version of their players.
Most people stream with their phones rather than with their computers.
To store on the cloud is an option for local files. Brio does it, and offers the desktop player, the phone player and 25 GB of cloud storage for free. You pay only if you want more cloud storage. But Brio does not stream Tidal and Qobuz.
There’s also the option to store local files on the phone itself or on a SD card, as Neutron’s phone version does. But Neutron does not stream Tidal and Qobuz. It streams only radios.
So Audirvana and Roon can find a working solution between these two technical alternatives. Maybe even an option that combines them both.
Actually, Apple’s Music app for the iPhone and iPad offers such a combined alternative.
You can stream with it Apple Music.
You can play with it tracks that you load to your iPhone.
And you can play with it your own tracks that Apple stores for you on the cloud.
EDIT
So there’s no reason why Roon and Audirvana won’t do the same.
It’s a huge market with hundreds of millions of users.
While the market for desktop players is tiny.
If I worked for them, I would have been paid for the ideas that I post as a free feedback.
Here in the Netherlands there are some telephone companies who offer music data free options together with their bundles. T-Mobile for example doesn’t count streamers like Spotify or Deezer when it comes to data usage. So you can stream all day without costing you your megabytes or gigabytes. Apple Music is not included in the deal.
My subscription is with a provider (KPN) that does not offer this. But I have 25 gb per month which is more than sufficient for me. At home I stream through my home connection which doesn’t have a data limit. And at work I listen to 320 kbit mp3 on Qobuz or 256 kbit AAC on Apple Music. Because my earbuds don’t support hi-res, so no need to waste my data plan on something that’s not going to sound different anyways 
Should I pass the 25 gb limit, I’m still connected to the Internet. But at a much reduced speed.
现在解决问题了没