It is worth noting that recent high performance pushrod engines seem to be avoiding roller rockers.

Maybe the rollers make the rocker either too heavy or less stiff.

Recent rocker designs seem to emphasize lightness and stiffness, as do pushrods.

In the book "Chrysler Engines" former chief engineer Willem Weertman writes that roller hyd lifters improved the fuel economy of the Magnum upgrade series of engines, particularly the 3.9 V6 version.

Roller rockers are certainly not new.
Rudolf Diesel's original compression-ignition engine had a roller rocker.