@Row
My brother's answer about WhatsApp and Discord:
She is right. Meta (formerly known as facebook) owns whatsapp, and has been for a very long time. But I don't see anyone praising or defending whatsapp's privacy. We all know it's shit. But we make an exception for it from other ecosystems for two reasons.
One, it's a mostly closed and safe circle. You have someone's number? Great, you can send him a message. Very straightforward with no wiggle room for shady shit under the table.
Two, whatsapp is by far the most ubiquitous chatting service. You almost cannot live without it. It's a necessity at this point. But when you do use it, you do so while being cautious and not sending any sensitive information through it.
Bonus: Whatsapp messages are encrypted by default. Encryption means that all our chats are locked behind a password. Meaning that no one can read our chat history except us. Of course, Meta's "encryption" model is just a joke. But it's better than nothing. Discord does not encrypt anything.
Summary: Whatsapp is a safe platform, but lacks in privacy. Discord is a very unsafe platform with almost 0 privacy.