Rust is far slower as a developer to write (far more complex and verbose), Nim has orders of magnitude less ecosystem/docs/community (Rust has much less too), and both have far worse debugging tools, REPL, etc.
Valid points, and the REPL in JS/TS is handy. But it's worth pointing out that when/if a project outgrows JS, there are more options than just C/C++. The smaller community/ecosystem doesn't matter nearly as much in embedded, at least for libraries. I've found all the Nim libraries I've needed or wrapped C SDK ones, and the debugger is the standard C one. Rust is similar, and more productive than C for many people once you get familiar with it. Though yes, you've got to be willing to figure out things in both. Overall it's good to see more options.
