I treat general service and tire shops of all stripes the same way one must treat gas station sushi and truck stop garden salads.
If it don't smell right...
Not a knock on the chains or big box locations at all, they are all different and you must trust your senses.
Case in point:
Local Walmart TLE would mount and balance tires for my vehicle, even if I got them shipped in. They are an oddball size so there wasn't any "Walmart" stock. Had an online retailer ship to store. I arrived as I got the email notice. Great!
Now I blame inexperience here. The tire tech was a fresh, perky and attractive young lady. The boys helped her haul my tires down from storage. They were busy but assured me they'd get it done. When the young lady tried to prop up my truck from a location you shouldn't jack it from, I ran out to the shop floor, waving my arms. "STOP! STOP!" If it wouldn't just fall from the floor jack, she would have caused major body harm for herself and the truck when it would fall and crush a door sill and body cladding.
I asked firmly but politely to please load my set of tires in the bed, I'll take care of it myself. I took it all down to a local indy shop and they took care of it all just right. Yes I'm one of those that lingers at the garage door and watches.
This same TLE is competent in oil changes however, but prefer still to just do my own. Unfortunately that very pretty girl wasn't working there a month later when I visited to pick up oil for my Impala, apparently she did manage to crunch a few too many other cars up under the fenders or kick panels.
The independent garage that did my tires is also a Valvoline Lube Express. I let them handle my differential fluid or anything I just can't handle without a lift. They are expen$ive
, but worth the money when I'm stuck. They also know I wrench and don't show up unless it's serious, so I get a bit of a break and respect. They've been worth every dollar every time. They get it right first shot and warranty all work.
So no, not everyone is a bad guy or crook, they can just be mostly inexperienced. Just keep your feelers out and observe. Then vote with your feet and wallet.