The network effect is a powerful force. If you want to talk to loved ones (or more and more, businesses) you are forced to use this platform, which hands inordinate amounts of power to the likes of Meta or other proprietary platforms that only ever have their own interests at heart.

I refuse to bind myself to proprietary platforms that I have no way to leave without insurmountable switching costs. Behaving this way is not without personal cost: It is more difficult to talk to me for others which annoys them or discourages them from trying. It also makes me look like a pedantic ass on platforms like these (although my phrasing there probably doesn't help I admit).

There are plenty of privacy and freedom respecting platforms that allow interoperability and I think it is better to use those rather than adding my bit to the network effect that makes WhatsApp the de facto standard, strengthening it further.