Ah yes that is also true.
So would also need to question the quality of work from dealerships as well or as you said get some more well educated employees.
Again having someone not educated working on your car (at home, dealership or other mechanic) will not help in resolving or fixing issues or servicing.
So again yes it is not necessary to go back to the dealerships but still having an educated person work on the car being either yourself or other quality mechanic.