Oh hey, that's my thesis! Happy to answer any questions you may have about it :) There's also the OSDI'18 paper here which may be of interest: https://jon.tsp.io/papers/osdi18-noria.pdf
Unfortunately I'm not privy to whatever improvements ReadySet has made in the past two years, so I can't comment on differences between ReadySet and Materialize. Perhaps Jon can, though!
I've been following the space since a bit of time, and I must say it's exciting. To me this is the future of apps where the Truth lives server-side, and everything reacts from there; With partial state evaluation lowering resource consumption to a minimum.
Kafka Streams and Apache Flink seem to be focused on real-time analytics, and I wish they'd get there to stimulate the space.
Are you affiliated with ReadySet?
Some context: https://twitter.com/jonhoo/status/1511401461669720068
Basically, I co-founded the company around the time I graduated, but had had my fill of database research after six years of PhD. So I joined AWS to work on Rust while Alana (the CEO) took on leading ReadySet.