I have had some success. It helps that many of the people I regularly contact were willing to migrate, even after some time. Most already used WhatsApp, so the friction to installing a new app was less than someone not accustomed to using a dedicated app for messaging.

But most of my American friends that don't have international contacts still just use SMS because they are not really accustomed to an app such as WhatsApp and so on.

It's incredibly disheartening how difficult it is to get most people to care about digital privacy.