SyncThing recently gave up on Android pretty much due to the same reason as NextCloud.

1) Nextcloud could make itself a share target for other Android file management apps, like Google's own "Files" app.

2) Direct .apk download.

3) Nextcloud could release their own file management app.

I replaced my Nest 2 years ago because Google had shut down APIs allowing me to interact with it.

Amazon continues to remove functionality from the Alexa APIs. Most recently, they've made it more difficult to add items to a "list" if that list is from an integrated app (in my case, AnyList).

I long for the days when these companies were eager for devs to integrate with their products and were actually making it easier to do so, rather than being silently hostile to their partners and customers.