I don’t try explaining this stuff anymore. I’m extremely bad at it and I know most people will either not care or not care enough. And that’s fine. It’s easier to let people think I’m a luddite. I prefer to wait for them to ask me why I use technology differently than to preach to them, and most of the time, they don’t ask. It’s always easier to let people convince themselves than to try to convince them.
I tell them to install Signal and message me there, and if they don’t want to do that, they can SMS me. Signal is a better idea if they want faster responses as I rarely check my phone but do check Signal Desktop fairly regularly. I have tried to get KDE Connect working so I can respond to SMS more timely but it was annoying and I gave up.