NB: the title is misleading. this is not about pure ideas, this is about economic growth, which to be measurable (significant) needs to be exponential. no doubt, there are more ideas now than ever. technology is a great enabler. but finding economically impactful ideas ... that does seem to be getting harder, from my armchair view.
Answers used to be expensive, but now it is pretty much free to get answers.
It may be that questions will become more valuable than answers.