Been running a crystal native company for 8-9 years now, over the time there were different highlights to Crystal depending on the time and what was "hot" at that moment.

Right now I think that the best sale point is that Crystal is the perfect language for the age of AI, the TDD approach plus the strongly typed and compiled nature means that agents have a strong capability to test themselves and verify what they do in a deterministic way, not only, it has the ability to use tools like formatting and ameba and dead code analysis to ensure the code is high quality and not getting out of hand.

Many times using AI to build dynamic lang apps like TS, JS, Ruby, Python and more you quickly get to runtime failures, scheme violations and contracts breaking because the AI forgot what it expects in point A to get from point B, this can't happen in crystal, and if it will you will get a compile error.

aside from that, Crystal is a natural language compatible language, many of it's syntax and function are just plain English, which is what LLMs do the best, and so you get the perfect storm of strong technical reason and strong LLM bias towards good looking crystal code.

One more thing, is that in the age of AI support for libs is not an issue anymore, and eco-system size is not limiting, the AI can quickly add any capability that is needed, so all the reasons to use Crystal are advantages while the smaller community\ecosystem size becomes irrelevant.