Outlaw it.
>And how does it apply to data a company generates about me?
You store it on a server you control, then provide access to 3rd parties. This is how https://urbit.org/understanding-urbit/ is setup to work.
Companies always follow the law.
If you don't want them to keep it, find a way to invalidate it. (This would be for where the read key is time sensitive.. not sure how to make that work)
The better angle is that we're becoming digital serfs. Google decided that they didn't want Google Music to exist anymore and poof went my listening history and playlists. Any service that I use today can do the same thing. If that data were stored somewhere I had access to I could have imported it in to Spotify.
This is an area I think Amazon or CloudFlare could step into. Sell consumers a NAS type box that keeps their data local. Sell companies on Lambda/Workers @ Home and have their applications run on that NAS.
At the moment we've been pushing services in the wrong direction to create their own schemas. However, we may win back control with standards on this one.
But yes, the idea is that you are able to remove the control they have over the data you've produced. It's such a terrible arguement to claim they own the data. (Also, why do they need to control that other than to try to prevent you from leaving)
There are very few types of apps which truly need a third party server to work.
This is perfectly possible.
In your example, Spotify could store the data they needed for their recommendation algorithm in aggregate form so that any link to a person was destroyed and not reversible.
And then make recommendations by running that algorithm on your locally/privately stored data, with no loss of functionality.
As such, a recommendation algorithm does not technically benefit from storing your personal data, at all.