After 12 years and 10's of thousands of miles a tire tech advised me that I should have my brakes and wheel bearings checked. Bottom line breaks were still good and the wheel bearings also. I do not...
I think it's whatever you want to do or feel comfortable with doing for your own rig as far as the bearings go.. You either check/pack them or you don't..
Pretty simple... Why argue about it??
I do the bearings on my TT every other year, but I've only done them on my utility trailer that I've owned since 1998 once... Go figure.. :)