Why do I have to wait on a developer

Less serious answer: That’s okay. It can be mutual. Some developers can dislike some of their customers, too. Firing customers can be a thing.

More serious answer: because the customers are not sufficiently profitable when compared to the work involved.

If it’s particular app, a whole lot of those vaporize because of the revenue model the app used in the app store, absent subscription pricing. Buying once and supporting forever is not viable for middling and larger values of forever.

Options for apps that are effectively deprecated if not actually? Either pay the developer directly to update an app that is important to you, or acquire the app and its source code from the developer and take over development, or move on.

It is best to move on. Sometimes they never do release a new/compatible version.

No clue what you are referring to. If English is your second language please post in your native tongue and perhaps someone will respond.