Yes, but sites like: https://github.com/iamadamdev/bypass-paywalls-chrome https://sci-hub.tw/ exist and make it trivial to get around draconian publishing practices. I'm not advocating not paying for journalism---it's just that not everyone realistically can, and paywalling them seems like a bad solution.

A more plausible reason, at least to me, is the increasing specialization of fields and lack of cross-field communication.

Also, ideas seem to be flowing plentifully at least in math and TCS, where old and hard conjectures are still being proved with astonishing regularity.