I can't imagine why anyone would take their car to a dealership for any service, save those which involve warranty claims as frequently in those cases, there is no other choice.
Dealerships are in the business to sell cars to make money, and frequently the service bay is so poorly run it's a liability to the bottom line - If the manufacturer didn't mandate thay they offer some sort of "service" I'll bet 90% of new car dealerships would close their "service department" tomorrow morning.
To make up for the poor management, and make it lose less money than it otherwise would, they charge exhorbitant amounts for labor, and charge you more for any needed parts than a well run repair shop elsewhere in town would. If you took a car there with a $5 defective part, likely you would get it back with half a dozen $50 parts changed out, and if you were really lucky, they might have changed the $5 one as well.
Labor rates at dealerships frequently run $60 to $75 per hour or more, while the mechanic actually doing the work on your car may make one-fifth of that - You can go to a professional shop elsewhere in the same town, pay half the rate and get faster and better work done, and know that it was done correctly.
I'm 30 years older than most of you, and I've yet to see a dealer service department that I would trust to work on my car, unless I was allowed to witness what they did, and most (if not all) are
very hesitant to allow that, and likely for good reason
Don