The ECS pattern became something really interesting to me just because of the highly serializable state.
One of the MUDs my community was involved in had a great developer behind it. It was just so amazing how fast new features were added to the system. The idea that you don't need assets, animations, etc is critical.
I would love for a book series that would cover something like this in multiple languages.
I admit on the few times I played it and managed not to get frustrated I do start to perceive it at least partly in 3 dimensions with immersion, like an interactive cinema in my head, bit like when I played AD&D as a kid (which I admit I miss).
Once you get into them though, they're some of my favorite games. NetHack might be the most absorbing game I've ever played, and there's a few others with that art style that came close.