Signal used to be the best answer to this conundrum, since it would use its own internal protocols if it could or fall back to SMS if it couldn’t, unfortunately they decided to drop SMS support a few years ago, citing users that sent sensitive information not realizing they were using SMS (that always felt kinda flimsy). I really disliked this change, because it raised the difficulty of adoption, from just getting people to replace their default app with Signal to making them manage multiple apps.

Now though, you basically need to advocate socially for the change you want to see in the world. Anecdotally, I started using Signal when they still supported SMS to talk with 1 friend group, and eventually convinced most of my closest family groups to also use it, many after SMS support was dropped. Apart from 1 tech illiterate elderly couple and 1 extended family member, I haven’t received any personal (non-company related) text messages in like 5 months.

I’m a little disappointed that they looked at each of social media, phone use and video game use independently as part of the study and didn’t seem to consider any covariance. If you’re looking for which things are really associated, seems like it’d be helpful to see where they overlap.