I use Discord, though only in a web browser and only for semi-public chats. I might be using Discord less if I had gotten some friend groups onto something like Matrix.

Unlike a car which is bought once and is mostly outside of vendor control once you have it, Proton mail is a service that requires continuous trust in the company since they offer a service. This means I no longer trust Proton as much, which makes me much less inclined to use their services.