ollama is just an inference engine - it just runs models.

it must ship with some default old model if you didn't need to explicitly download one

This is one of the jagged mismatches between users and LLM developers. The median user doesn't care or want to know about static models and knowledge cutoffs and whether a model can do tool calls or if tool calls even happened. They just want something that works.

Fortunately increased capabilities seem to make this a basic expectation with new releases.