I am a professional groomer. It is not at all uncommon to have dogs dropped off in the morning and picked up in the afternoon. The reason this happens is for practicality. Many groomers do not receive an hourly wage, but are paid on commission-the more dogs we do, the more money we make. For myself, I tend to work slowly and methodically and when I used to work at the vet clinic I also tended to be assigned the scared dogs because I took the time to go slow and be patient-so I generally only groomed 3-5 dogs a day. You absolutely do not make enough money to make a living grooming so few dogs a day, but I feel that is all I could do and still do a good job (plus my husband is blessed with a good job so I do not absolutely NEED the income-some groomers DO really need the income because it is their only source of income). Unfortunately, that is the reason why some groomers do a horrible job because they are only concerned about money and take no pride in their work, or else they just need the income so badly they can't take the time to do well even if they want to. Anyway, having all the grooming dogs dropped off in the morning allows for a more efficient bathing and drying process-we can get all the baths and blow dries done in the morning, and then start on the haircuts/brushouts. Generally, I would start my pick up times at 1 in the afternoon, and then go hourly after that; I would also call the owner as soon as the dog was done so that if they wanted to come pick up earlier they could. We would leash walk the dogs outside, individually (so not multiple dogs out at once) at least once during their stay. And just for your knowledge, it takes me an average of 3 hours from start to finish (including bath and completely hand drying) to groom an average golden-thicker coat takes longer, unruly dog takes longer, scared or aggressive takes longer. I am slower than the average groomer though, but it still gives you an idea of how long the dog is actually being worked on (lots of people are surprised by how long it can take). Yes they stay in crates (small dogs) or runs (large dogs) for their own safety-we can't let a bunch of strange dogs run around with each other because a fight could break out. Also, for older dogs or dogs with issues walking or standing for long periods of time-I think they appreciate some down time to lay in a crate or run after their bath/blow dry and rest before they have to stand on a table to be groomed.
Anyway, just an insider's thoughts.
If you are really concerned about the time, talk to the groomer and ask if she can give you a call as soon as the dog is done-don't pressure her to rush, but just say you would love to come get your dog out of their hair as soon as she's done. (And trust me, we groomers all have a few dogs that we actually want to get out of there ASAP-like a certain yappy little Yorkie I'm thinking of right now! lol! or that Cocker who poops and pees on himself every 5 seconds no matter how often you take him out!)
I now work out of my house around my full time mom schedule so things are totally different for me now with regards to how I groom-I'm generally only doing one dog in a day and I could go weeks in between bookings; so now my clients just get called when their dog is done and they come pick up when they can-the dog stays in my house loose if they are well-behaved.