There are still memory leak issues with current concurrency model, which is closer to GO, than true parallelism available in C++, Nim, Rust, etc.
See these threads for examples.
I would love to see a roadmap to provide true multi-threaded parallelism, even if its for 3.0, that doesn’t use channels as the means to synchronize operations.
There are a whole class of parallel algorithms|applications I would love to implement in Crystal that run best now in Rust|Nim|C++.