> But it's not a solution for beginners or less-technical people.

I don't see a problem. You don't give beginners enough credit. We were beginners once and we managed it just fine. If anything beginners today are cleverer than us :)

> Lack of server-side history also makes it basically impossible for new members to read into the conversation history

Is this actually something people do? For one of my channels I had stats generated from the logs and ability to search the entire log. I'm sure that could be trivially setup nowadays with Elasticsearch or something. If you control the server you can guarantee you'll catch every message too and won't lose any in a netsplit.