The latest generation of energy recapture tech for regenerative braking works better with a hybridized mix of blended + dynamic brakes in order to recoup the maximum amount of braking energy as recirculated electricity for traction and/or HEP (with all the associated fuel/emissions savings that entails). So you don't see much 'pure' dynamic braking on the state-of-the-art current generation of loco families. Siemens Charger + Sprinter, EMD F125, Bombardier ALP-46A & 45DP, MPI HSP-46, the latest GE Evolution freight makes like the Tier 4 ET44AC + scores of older ES44AC's being rebuilt to newer-spec, tons and tons of newer Euro power, and on and on...they all go with some optimized-to-task mixture of dynamic, blended, regen, and electropneumatic braking systems. It's simply how 21st century power gets built.