I see where you're coming from, and I sort of agree-disagree.
I mean, I see the benefits of undervolting, but to do that, you first have to configure your cooling and PSU size around the normal power consumption of your components. You first have to turn your PC on at stock to even start the undervolting process. If your PSU and cooling can handle it, you might as well just leave things at stock.
My real problem is that a big chunky GPU with a hundred power connectors is a big chunky GPU with a hundred power connectors whether you undervolt it or not. I don't like big chunky things (except for food and the rear side of women).
Overclocking on the other hand, is completely useless nowadays, imo. I could see the point in it 10-20 years ago when everything ran at fixed clocks and the only differentiating factor among components was clock speed. These days, you have such aggressive turbo algorithms out of the box, that overclocking will only give you a marginal, if any, benefit. You can also lose your single-threaded boost bins on your CPU if you overclock it, which is a waste.