You obviously haven't seen the charts of the metadata that WhatsApp collects. And we know how anti-consuner, adversarial and anti-privacy Facebook is overall with their tracking pixels, ghost profiles, etc.

Telegram at least doesn't have the FB dataset. FB knows about me, though I've never once in my life been on their website or used anything related to them. Not once. The first I heard of FB I saw immediately the privacy problem with them, and made sure to never have anything to do with them. But they know about me from other peoe posting pics and such, which they then correlate with sites I've been on that have tracking pixels. WhatsApp ads a metric shitton of metadata to that pile, with date, time, location, duration of conversations, businesses you're near at the time, their operating hours, etc, etc. They have a massive, constantly growing dataset, which they can easily correlate elements.

WhatsApp may be encrypted, but I trust Zuck so little that I wouldn't doubt they capture keystrokes in app before the message is sent. They have the capability as was shown in a recent research article (though no evidence of it happening).

Id rather not use Telegram, but it's far lesser of the two evils. I'm trying to get folks to other apps. Signal doesn't sell, SimpleX isn't quite ready, I think Wire has the same stored encryption key issue, though I may be mistaken (I'm not fully clear how it's managed).