I live in SF bay area and go to Stevens creek Mercedes dealer for my old car 2016. This is a very strange experience in this Mercedes dealer and not sure if anyone sees the same.

1. During service maintenance, technician will post a video about areas that need to pay attention. The service advisor will provide estimate to address these issues. However, I found many times, advisor has conflict advise than technician. For example, one time technician was mentioning brake pads are at 5/6mm and looks ok. When advisor follows up, immediately wants me to replace 4 brake pads and saying pad is down to 3mm. When I confront the advisor (I actually know and measure myself), advisor changes story and saying it is ok.

2. When advisor gives estimate, it never gives an exact labor, hours, parts cost. When I ask for it, advisor just not answer my questions and want me to take it or do next time.

I like to know if this is just this advisor or this is the same for all advisors in this dealership. I always compare labor and parts cost with other certified shops. I go to dealership sometimes when they really have a good deal to attract me (service A for $140). I understand dealership usually charge more compare to other 3rd party shops and up to me to decide if I pay more for convenience or not, but sometimes I feel these advisors are taking advantage to anyone that has no idea on their cars and take whatever they suggest for the repair. There is no transparency on the pricing. Some quotes seem reasonable, some are ridiculous. I still don't know how much Stevens Creek Mercedes dealer charge for labor per hour. Even though I have doubt, I see service department is usually packed on all the days I come in(both new and old cars). It makes me wonder if I have a bad advisor or too many rich people just don't care about thousands of dollars repair on their cars.

You have to notice, that all those "courtesy inspections" or "revenue seekers" are mostly scams and I don't recall when was the last time, when my perfectly working MB come with 1 lower than $5000.
On my sedan, who is not driven much, 3 years ago such inspection reported 3 mm pads, with $$$ attached to it. Last year another inspection reported 6 mm pads and good to go. Those are still the same pads.
Since I DIY all the repairs, I do recheck the reports. From my observations, lot of them are done from comfort of office chair, when nobody is actually taking a look on the car.
SA will pull MI and base on mileage, when he doesn't see record of part replaced, he puts $$$$ on the item. I had new parts, judged for replacement.
When I was living in Bay Area, I would drive to MB of Fairfield as they seem to be more honest, than others and they always gave me the best price on new key.

In California as far as I know the labor rates have to be posted at the shop. Both my dealership (MB of Walnut Creek) and my indy have them posted in large font on the wall to see. The estimates on the inspections are just book estimates. The SA just pulls them from the system. They don't even know the breakdown themselves. If you decide to get the job done, the estimate will be broken down on the work order and at that point you can authorize or decline it.

As said above, the inspections and estimates are sometimes half hazard. I pay minimal attention to them. They are very conservative when it comes to brake replacements and such. I don't do wear & tear items at the dealership. I source my own parts for brakes and tires and then take it to my indy. They are very transparent and I know the owner etc. They are also a performance shop doing track preparations for cars etc. So as an AMG and performance car owner in general, there's a mutual respect and nobody is BSing each other. Not that I'm getting pushed around by my SA at MB of Walnut Creek, either. He knows that I know my car and even the service director knows me by name and greets me in the service bay whenever I drop off the car. It's all about having a good relationship.

To answer your question, though, yes they are a business at the end of the day and need to have a solid revenue stream and profits, so customers who know nothing about cars and don't care about the cost might just let them do whatever. While the book prices at dealerships are high, I haven't found them to be dishonest with me ever. Maybe overly conservative with recommending to replace my brakes or tires before I would have done it, but it's all relative. Depending on how you drive the more the pads are worn the less effective they get at dissipating heat. My SA just gives me these recommendations and estimates as a courtesy. He already knows that I won't have it done through them. On AMGs they quote brake replacement north of $5000 for example and I get it done for less than a quarter of that at my indy and the place I get the parts from has lifetime replacement warranty, so the parts are essentially free after the first set.

The other side:
I had my ML in for an AEM issue (DEF injector wasn't injecting) and the SA pointed out a couple of issues that needed addressed: The transfer case/transmission seal was leaking (it was, and they could fix it for about $1200) and the right rear airmatic shock tube was leaking (it was, and they could fix it for about $1800). I declined both repairs but have since replaced the shock myself (bags and shocks, Bilstein, $1800 on Amazon), and I have the $40 seal to fix the very slow transmission/transfer case fluid leak. I found Ken Garff Mercedes in Salt Lake City to be helpful and honest. $0 bill of course for the AEM repair, and I was grateful for the heads up on the leaky bits.