You are using the word evidence as if it were evident. It isn't. It is the crux of most problems reaching consensus. If you don't believe that, just try to give me a careful description of you would consider acceptable evidence to be.
The topic of how planned obsolescence (a special case of artificial scarcity) could be measured is worthwhile, but not trivial.
What I would consider the best 'evidence' for me is the simple fact that If a company can sell 2 things instead of one, it tends to profit (up to) twice as much. To the degree that that is true, it guarantees the inclusion of artificial scarcity in markets given enough time for it to arise.
A better question seems to be are there any markets where artificial scarcity doesn't arise? If so, what special traits of that market act to suppress it?
Ford likes to claim they sell the longest-lasting trucks. Their market isn't just former Ford owners, but current Chevy and Dodge owners, current Nissan and Toyota owners, and a growing population. To say a limited lifespan is ipso facto proof of artificial scarcity and planned obsolescence doesn't pass muster.
I do know engineering to reduce costs happens, but the mandate is usually "meet this high target within these material and cost parameters," not, "pare it down to this this bare minimum," unless you're talking about Harbor Freight junk.
Don't shift the goalpost or the burden of proof. I never denied that planned obsolescence never happens or that artificial scarcity isn't a thing, i said it was a more complex subject than typically understood, and not the open-and-shut case it is considered to be. Yes, it is difficult to measure. that is why you need to offer verifiable evidence that it has happened in order to demonstrate any specific allegation that it has occurred.