Apple stores had specific function and well-defined goals. Brand, hands on, direct sale, all spring to mind. Microsoft stores seemed to have a motto of "Copy Apple stores". I didn't get their reason for existing.
Their reasons for existing were the same as the ones you listed for Apple stores: Brand, hands on, direct sale. I'd also add that they serve as a place where buyers believe that they can get support on product, thus increasing their trust in the product. That's an incredibly valuable thing IMO.
One of the hard things for MS I think is that the Apple store was successful because you couldn't get a Mac in the past anywhere else and it was a good experience that really set the tone of the Mac.
Then the iPhone and iPod happened, that blew up the Store market for Apple. Microsoft doesn't have an iPhone, didn't have a successful consumer market beyond the Xbox and most can and will get a Microsoft product somewhere else. Worse even, it is a hard place to read for the customer. What do they sell? Obviously products running windows, but I don't think that really tied back to Microsoft's own products, surface, Xbox, etc. When the stores first were created the notable thing I realized about them was this: People, normal people, don't actually care about Microsoft. They use their massive body of work, they live the Microsoft life, but they don't actually see it as cool or interesting. Few normal people are like 'Woah, look at the Surface Neo!'. They have a major uptight brand problem, maybe the Mac v PC ads helped cause that, perhaps an engineering-led culture rather than a product or human-focused culture?
I think the lesson MS learned here is that you can and could copy everything about an Apple store but that doesn't make you Apple and doesn't bring their unique context in which the stores work extremely well.