no, the knowledge frontier expanded. To reach the point where you have a good idea you must be exposed to a lot of existing knowledge (as well as bad ideas), which by itself increase every year.

Hence just to become a professional in a subject, you must spent 10-20 years (probably also getting an advance degree), until you can start having good ideas.

So I would say that the amount of good ideas is inverse to the amount of existing knowledge taken by some growth rate.