Tell me how you can set up an Android device and install apps that require Google Play services (like all the most popular and important apps) and not have Google syphone all your contacts details. I mean everything: name, date of birth, addresses, emails, websites, relationships,etc.

Answer: you cannot.

Any time you log into a Google account just to use the Play Store, Android will instantly starts syncing all your contacts and you can't prevent that. You can't even toggle airplane mode as a network connection is required to login. And you cannot configure Android not to sync all contacts data with new Google accounts by default.

I bet Google has syphoned the details of every single person on Earth (without their consent) and I have to trust them not to use that?

F** em

That is all nice and well, but Google is primarily an advertisement business. A huge corporation that gained enormous power that operates only to satisfy its own self interest. So that gives us non-Googlers more to think about than just that consideration to take into account.

What do you mean by "better [...] at handling sensitive info"? As in, they are more technically competent, or they will treat your data more ethically?

I don't think these projects claim they've got better infrastructure for handling private data, just that they won't sell it to advertisers. I trust Google are experts at handling my data, I just don't want them to.

On the other hand, I would trust a randomly chosen organization more than the world's largest adtech firm.

Better at siphoning out all the sensitive info, maybe.