The biology of HDL is complex and not understood, unlike LDL biology which is considered trivial and primarily addressed by lowering it.

“the hdl biology that is really complicated that's what the 21st century is going to be about we don't have a clue what we're talking about with hdl we've been using this idiotic crude metric of how much cholesterol it contains it is now completely clear that that was the wrong metric then any attempts to increase it were futile”