Seeing the performance improvement numbers I'm pretty sure there's a type-inference system below it to realize types in all paths (same as the AOT JS compiler I created).
It's not to be beholden to types per-se, but rather that fixed types are way faster to execute since they map to basic CPU instructions rather than operations having to first determine the type and then branch depending on the type used.
The problem with dynamic types is that they either need to somehow join into fixed types (like with TypeScript specifying a type-specification of the parsed object) or remain dynamic through execution (thus costing performance).
It's not to be beholden to types per-se, but rather that fixed types are way faster to execute since they map to basic CPU instructions rather than operations having to first determine the type and then branch depending on the type used.
The problem with dynamic types is that they either need to somehow join into fixed types (like with TypeScript specifying a type-specification of the parsed object) or remain dynamic through execution (thus costing performance).