It takes time. I've been "indoctinating" my family fo years. And that really just means reinforcing things we all, "regular" people included, know about big tech. Part of that meant straight up telling them I wouldn't use anything other than Signal. That worked, and a few years later I now have my mom on Linux. Sometimes doing the right thing means being stubborn and putting your foot down

Edit: my parents have both become open source evangelists, and my mom has asked me more than once the difference between Free Software and oss. My parents are also both pretty conservative so it wasn't easy to turn them. But like I said. Put your foot down. Tell them you are doing the right thing, and if it comes to it, withold tech support 😂