I recently started using WhatsApp regularly because it's the only convenient end-to-end encrypted messaging app I know. The only thing they seem to be getting out of it is some metadata and the opportunity to sell services to busisnesses. Seems like an acceptable compromise to me.

Previously I used Matrix/Element but never got it to work reliably with my friends (decryption issues, session verification obsession). And Signal has no web app. So WhatsApp it is for now.