Is this the same code as well as the same data?
Generally moving from enum to streams trades speed for less memory need. Things are not meant to become faster (but rather become slower) in favor of not needing to load everything into memory at once and being able to process data, which doesn’t fit into memory comfortably or even at all.
If your data fits into memory Enum functions are expected to be faster.
Similarly moving to a multi process architecture adds overhead in process communication (there’s no reduction) in favor of being able to use multiple cpu cores at the same time.
If your data doesn’t even max out a single core for processing it’ll be faster in a single process than with multiple ones.
Especially the last one is a bit simplified as there’s also things like io involved, but I hope you get the idea.
