Not sure what point you are making here.
If it is that there is no control for an A being easier to obtain at school 1 vs school 2- yes, this is accurate. This is what standardized tests were intended to accomplish.
6.0 weighting, in my opinion, is an example of a fairly recent tactic used to superficially inflate GPA, i.e., 4.5 sounds more impressive than 75-80% ( not all classes are weighted).
Normalizing on a common scale eliminates this variation- this was my point. Also, I believe there were earlier questions about how UF calculates GPA