But when Apple ships the replacement battery with the Apple self service tools that they have today. Would that even change something for the iPhone? The amount of expertise is questionable.

The same problem is in politics in Germany. They vote only for the big politicians who have already a big group of supporters and so a high chance to win. Like „ I don’t vote for xyz because they have only 0.5% of voters in Germany and can’t change anything by that“ . With this attitude they also grow very slowly.