The pricing page says you can only share it with 5 users for the $10/month package. Am I missing something?

You are right, apologies. :) x24 more than WhatsApp for the benefit of being sure your data doesn't fall into third party hands, that's for you to decide if it's enough.

"your data" falls into at least elements and aws hands with this. Yeah the content is encrypted but there's lots of metadata to grab by malicous actors. The reality is 10$ for 25 Users would have been more reasonable. Enough to setup a server for your family and close friends.