I do know what you mean, but whilst that kind of lather feels luxurious in itself, I find it lessens the feel during the important bit - the shave. If I don't have enough feel when the blade is on my face, the more likely I am to have a poor shave.You are probably right that you get an equally slick shave with a smaller amount of soap, but for me I have to build a rich yogurt/creamy lather that makes the whole shave complete.
It's hard to say why this means so much but I think it's because I use all my senses when the soap turns into a rich lather. The scent, to feel, the sound of lathering my face, and the sight of a beautiful white lather that also performs above all expectations.
It's a balancing act. Today I was using a different shave to normal, and it was fine with a DE razor, but pathetic when I tried a shavette. I find different soaps/creams need mixing to different viscosities to give me the performance I need. I happen to prefer the products that give me that performance with lower viscosity and enough blade feel for me to be precise in my shaving. I get my best shaves that way.
I know the lather in the opening post would give me a fantastic shave with any razor, but today's soap lathered like that, would be like shaving with dishwater.