Crystal wanted to be Ruby/Go - essentially a faster Ruby, that sort of scales, too.
CLEAR aims to be a substantially safer Rust - no Garbage Collector - no manual synchronization hazards, and safer than even Pony - but also with far less complexity than Rust.
Crystal's fibers did not do well multi-threaded until somewhat recently, and AFAIK, it's still very far behind Rust/Tokio and Go in a lot of important benchmarks. Crucially, afaik, p99 in adversarial workloads can still blowup easily.
Like Tokio, CLEAR lowers fibers into Finite State Machines instead of stacks, which perform better than stacks in wait heavy (i.e. Go's primary market - web servers) and idle-heavy scenarios (i.e. chat servers, telecom, etc), and it has Go's work stealing algorithm + forced yielding to ensure p99 doesn't blow out.
Also, CLEAR transpiles to Zig, so it has native access to the entire C library. Crystal has a bootstrapping / ecosystem problem that's unlikely to ever be solved.
CLEAR doesn't need a single person to contribute to it to have access to basically everything.
Also, transpiling to Zig means you get Zig's other killer feature - you can compile to any target (i.e. Linux) from any target (i.e. MacOS).