Are you going to argue with everyone if they tell you that dealers don't employ mechanics, only fitters
This isn't actually true - most franchised main dealers, particularly the larger ones, will employ a mixture of both mechanics *and* fitters. The fitters will get the easy work.
and that you are more likely to get better service from an independent with lots of positive reviews?
I'd say its 6 of one, half dozen of the others. There are numerous crap main dealers out there who will gladly take a fortune off you for doing very little but there are equally many 'independant specialists' out there which are nothing of the sort and equally if not more incompetent than the main dealers you dislike so much.
There are fabulous independants out there who are worth their weight in gold but there are also decent main dealers, too.