If you don't have any specific knowledge of the details of the implementation, your opinion on the technical justification of a given feature isn't really all that compelling.

If you do, you should probably cite it in your comment.

We could discuss the technical side, sure. Maybe they can cache the list or create better code to do it more optimally. There might be battery and data usage considerations too, that's true.

But this article revolves around the trope of "if it's free you're the product", and altough it might be true, I don't think the 23k thing is a proof of it. That's what I meant with my comment.

Doesn't mean it's sending the address book to their servers 23k times, just that the app needs to resolve phone number --> name.

Or it means they lazy load each contact as you scroll through your contact list, so that scrolling through the contact list once = 150 "accesses"

I think a more reasonable explanation is that the author of the article uses WhatsApp more than he realizes. It's possible that WhatsApp is maliciously polling your contact list all the time, but it's more probable that some views access your contact list and the article's author ended up on that screen very often.