There's a 'pyramid of necessity' with "materials production" at the bottom, and at the top things like branding and marketing. In an expanding economy, such as we've had for the last 60 years, the top adds all the value (so, for example, you can just outsource the bottom). Generic bleach is often overstock from Clorox. Same product, but you're paying more for the name, image, etc. Service and finance industries fall in toward the top of the pyramid.
In a contracting economy, as we have now, the pointer on the pyramid drops relative to the size of the downturn. If it's severe, it's really only material production / commodities / etc. that matters. Who cares if it's a Nike? I need a shoe.
So it's not about "real value" meaning no value, but rather "real" vs. "nominal" value. The bottom of the pyramid has concrete value whereas the top has merely the nominal value of what people are currently willing to pay for it.
Real value is created only in manufacturing, industry and agriculture. Service, finance and so on are add-ons to those fields.
Then you said:
I did not say that all service industries do not create value.
Actually, you did, in the comment I just quoted, less than a day earlier. What is wrong with your brain, child?
Value is created by scarcity.
Not only is that a stupid theory of value, it also fails to justify the conclusions you're trying to justify with it: waitresses (and the services they provide) are quite a bit scarcer than, say, corn.
Maybe you should test your theory of value by trying to give up something abundant for a few days. Try oxygen. Then you can tell me if oxygen has any value.