The power requirements of the machine you describe would easily be more than double that of the Mac, but you probably aren't getting anywhere close to double the performance.
Besides, if you care about performance, you’re going to want to do more than just replace the RAM
Unless you live in a cave and using your excrement as manure I could apply the same logic to your lifestyle.
Realistically the only practical difference is virtue signaling (I've seen a bunch of hipsters bring up these kind of irrelevant talking points while discussing their vacation in some exotic destination 5 minutes later).
And like someone else said, Apple devices are the definition of throwaway consumer products designed for a limited shelf life.
I wish I had a 5950X that requires less power. I don't. I am going to choose this CPU over any mac any day because it's faster. A lot of other CPUs consume less electricity, I don't use them neither. End of the story.