Why use a dealership to just change oil? That's a waste of extra money right there IMO. Nothing says you can't take it anywhere,or do it yourself as far as warranty concerns. I hope my car never sees the dealer again,if it does,unfortunately it will be something warranty related. Ugh...
Not every dealership or car maker is the same.
This is just my personal experiences with my Nissans, but I've done oil changes at the dealership for 10 years.
In my case, the dealership has a drive through quick lube facility, similar to independent oil changers.
The cost is the same, and in some cases, less.
I'm in and out in 15 minutes.
The big reason for going there is I don't get the sales pitches that you get from independent, profit oriented businesses.
No pitch for a transmission flush, or new wipers, or air filter, cabin filter, brake fluid flush, etc., etc.
I also stand right next to the pit area and watch everything they do.
The other reason is that the oil changes are logged in the dealer's system. If I ever have a problem (and I've had none), then all the work is logged in their system.
Maybe your dealership is crap, and you've had a bad experience, for which I am sorry.
Hopefully when I get my new ride (95% sure it will be a Mazda 6), the dealership will be just as good as the Nissan folks I have dealt with over the years.
Cheers.