[dehrmann]

Arguably, this is because all the low-hanging fruit has been picked, and all the remaining problems are too complex for a single person to solve.

[jiggunjer]

I'd say it isn't complexity, but resources. New data needs highly specialized equipment and materials. Even then the accuracy and precision may be lacking.

If we could manipulate the microscopic with the ease of the macroscopic we'd be making many more discoveries.