Maybe for bubble code it'd be okay to just say "gimma a hash".

But most real code needs to interoperate with stuff. E.g. I need to send a SHA-256 from a JS client to a Python server. So there needs to be a consistent and portable "SHA-256" concept that everyone understands.

A cryptographic hash is not a complicated concept (even if developing one is).

I suppose you can think about whether you require collision resistance or merely second pre-image resistance, but the popular ones are all intended to be collision resistant anyway.