What happens when the user decides to move to an Android device, or even is suspended from Apple for a suspected breach of the terms of service, or Apple decides to not support their country anymore? There are countless reasons to prefer to manage one's own access.

True... Theoretically correct but in practical sense?

All these doom mongering of suspension happens so rarely that majority don't care.

There are countless reason to DIY. Agree. But passkeys will help the majority.

Also note that the kind of people - like journalists etc - that need to use DIY/local are the ones that are likely to use passkey. Reality.