@crispy I''ve found with family members or friends that intellectual explanations don't work, but just saying "This is what I use now" does.
For a gaming group, they all used WhatsApp and were thinking of making a group just for that on there. I don't use WhatsApp. I told them "I use Signal. If you want a group, I'll make one on Signal. It's free to download, here's the link".
Within a day, everyone was on Signal.
Hosting is a more complex matter though, hence my post.