> I personally had plans to build some open source stock Android applications, but after whole nonsense with platform being locked down I do not see the point in investing my time, just for google to block my apps.

It doesn't apply to GrapheneOS users and it doesn't affect developers who have apps on the play store. You should do it! Many users on stock android who would install apps not from the play store will have gone through the 24 hours or used ADB.