my additional 2P .. try Magura's Hydraulic Rim Brakes , (hydrostop// HS 33 )

there are other systems you may want to try before such a sweeping generalization .

New this year Sram has a hydraulic master in the Brifter on their top tier race group
and offer a Hydraulic rim brake as well as a disc caliper.

Magura has a new race bike Hydraulic brake this year as well they went aero for that one
and only seem to offer a end of the aero bars type brake lever.

HS 33 bolts to V brake Bosses.. I have them on a trekking bike from NL.