Do you trust apple with their claims?

No. I inherently distrust trillion dolllar tech companies in poorly regulated economies. They are able to get away with a lot of crap and they know it. That’s how the Cult of Apple works. I would not be surprised when they violate their own privacy policy knowingly and structurally.

I hate that kind of not-invented-here syndrome. The project I am helping develop is partly open source and has its own server-side framework, its own ORM and its own typescript based framework. Community-wise we are dead in the water, because nobody wants to adopt to the own frameworks.

Incidentially, I used OpenERP5, which is an early predecessor of Odoo. I hated the interface with every fiber of my being. Due to some custom development, we were not able to upgrade to more modern versions.

Take a look at Group-Office. It has a community edition that is self-hosted and a paid professional edition. You can either self-host or host in their cloud.

https://www.group-office.com/

Full disclosure: I am one of the developers.