Earlier quoted context omitted.
Ruby also suffers from top quality JITs vs what JS has. The only good option being JRuby, as far as I understand. I am not at all into Ruby. Regarding being polyglot and seniority, a possible solution is to work for consulting companies that focus on multiple stacks.
MRI has just added a JIT, I know nothing about it other than that it exists.
Because MRI Ruby is a threaded VM, it's easy to replace jumping to an instruction which dispatches to the next instruction, with jumping to some native code which dispatches to the next instruction.
Right now, AFAIK, only very basic optimizations are enabled but just removing the overhead of VM dispatch between each instruction is a huge performance improvement.