I think this is the best long-term solution, but support should also come from Spotify. When Valve saw Windows going in this direction a decade ago, they decided to officially support Linux. And even though the Linux market share is still quite low, it lowered the barrier to switching by quite a lot, essentially acting as a loaded gun forcing Microsoft to behave.

Imagine if Spotify started officially supporting the PinePhone and started advertising that. It wouldn't get many people to switch, but it would start putting pressure on Apple/Google to be a bit less evil.