The biggest problem since day one with bearings was that there is a difference in axle thickness to what the dia of bearing where it goes over such axle.Thus creating a not so perfect fit.( mainly because the first precision bearing came from a Hoover vacum cleaner, and bearing specs have been the same ever since. Imagine a set of R/Rons in your hoover!)
Thats where Biltin have come in and tried to rectify an age old problem.
I dont know why bearing companies dont make a bearing with the right fit, how hard would it be.(without all the gimmicks of Biltin) Surely skaters deserve a better deal when it comes to research and development, we buy enough bearings as a collective world wide.
It would have to be cheaper than making trucks with a thicker axle!
Any way, thats my thoughts on the subject!!