My family and a few friends are on Facebook and I don't see a reason why I should ask them to switch to ... what exactly?

They found old friends on the platform and they keep sharing pictures and stories and seem to be having fun.

That is useful and I'm willing to scroll past ads and even - shocking I know - click on an ad.

I'm pretty sure I'm a regular user and FB has hundreds of millions of those.

Mastodon.

Classic HN, where their grandmas and the rest of non-tech family members all successfully switch to Mastadon en masse.