Although arguably these flags are more reasonable than allowing the use of -march=native.
Also consider the inherent advantage popular languages have: you don't need to break out to a completely niche language, while achieving high performance. Saying this, this microbenchmark is naive and does not showcase realistic bottlenecks applications would face like how well-optimized standard library and popular frameworks are, whether the compiler deals with complexity and abstractions well, whether there are issues with multi-threaded scaling, etc etc. You can tell this by performance of dynamically typed languages - since all data is defined in scope of a single function, the compiler needs to do very little work and can hide the true cost of using something like Lua (LuaJIT).