I like the optional garbage collection of D, the fine-grained control over memory layout and metaprogramming abilities of Jai, the goroutines of Go, the content

I like the optional garbage collection of D, the fine-grained control over memory layout and metaprogramming abilities of Jai, the goroutines of Go, the content-based dependency management of Unison, and the memory safety and general ergonomics of Rust. My ideal language would combine these in some way, but with some changes, e.g. garbage collection should be scoped instead of on/off and newtypes should be first-class. It's difficult to have this much functionality without going overboard on complexity like C++ has done, so careful thought would need to be put into how to harmonize all these features and what compromises need to be made. The most important thing would be to adopt an edition system like Rust has, not just for the language but also for the standard library. This would allow breaking changes to fix inevitable design mistakes.