I'll provide a counter-anecdote that almost my entire social circle - at least 30-40 people, mainly middle-aged non-tech people - has migrated to Signal from WhatsApp in the last 2 years.

And it didn't take much effort. The desire for a cross-platform (iOS/Android) group chat system, Signal's features like desktop apps and ease of use, and a generally growing dislike for Facebook/Meta made it pretty painless and organic.