I think the biggest difference is that Materialize can do any kind of SQL join on many tables at once. Clickhouse materialized views can only reference one table.

What I'd like to know is if that would enable basically implementing social networks as just 3 tables and one materialized view, and how it would scale and perform.

Users, Relationships, Post, and a Feed materialized view that simply joins them together with an index of user_id and post_timestamp.

As relationships and messages are created or deleted, the feed view is nearly instantly updated. The whole entire view service logic then is just one really fast query. "select user,post,post_timestamp from feed where user_id = current_user and post_timestamp <= last_page_post_timestamp order by post_timestamp desc limit page_size"