I’ve been invited to join a couple dozen non-technical people who live in the same area who have started a group for events and meetups and want a better messaging solution than email. Facebook not an option, I’ve been told.
I’m tempted to suggest free Slack, we don’t need a searchable archive that goes back long.
But honesty I haven’t tried half of the currently popular messaging tools, and don’t have time to try them all to form an opinion.
What do or would you use for this type of thing?
I would start with assessing which messaging tools they are already using and see if one of that feeds your needs.
While Slack (or other similar tools like Discord, Teams, Matrix) would be theoretically suitable, it doesn't help when no one uses it. A set of WhatsApp/Signa/Telegram Groups for different kind of topics might be the better solution.
If you are deciding towards a new Tool that most of the people aren't familiar, I'd suggest to organise a little install party to get everyone ready to use the new tool and to overcome the potential initial scepticism and to gain momentum. Also make sure to define a concrete cut-over date to avoid creating just an additional channel.