Yep. In Rust land for instance it'd get compiled down to a for loop and be ridiculously fast. Every time you do a .map or a .filter in JS though it gets abstrac

Yep. In Rust land for instance it'd get compiled down to a for loop and be ridiculously fast. Every time you do a .map or a .filter in JS though it gets abstracted down to a function that makes an allocation for the ENTIRE ARRAY and then copies the entire array into that new array doing whatever you asked to data. The JS VM might be able to optimize some of it away but the abstraction is awful. So if you were to manually run a for loop over an array instead of iterating through it I'm not surprised you got an order of magnitude faster performance.