Your only vqlid point there is "wearing out the spring."
Which no longer happens on anything but the cheapest derailleurs from Shimano. The spring in there goes from deflecting about a third of a rotation to about half. This isn't the 80s when the springs were 1 coil snall guage straight steel anymore.
My drivetrains are all very silent across their entire gear ranges.
And here's something you're wrong about. The recommendation for 2 and 3x drivetrains is actually 2 link pairs. Because you have a chance of the chain riding the teeth and bending teeth or a derailleur during shifting, in theory. Basically impossible on 9 speed plus and mostly a problem for older drivetrains.
Finally, "any alop in the cage"
Again. This isn't 1980. On all but the cheapest parts none of what you said is a concern, as evidenced by my three functioning bikes with only an extra link pair past the minimum.
Oh, and contrary to what you're arguing. Modern 2x drivetrains are all meant to be run big-big. SRAM especially says so in their instructions and in interviews. You're making a retrogrouch argument, similar to guys still talking about KOPS.