I'll play the devil's advocate here.

The point about bringing up things like dryers and washing machines using energy is pretty simple: Using energy is not a bad thing. You, person who is arguing against bitcoin because of its energy use, are actually in favor of using energy for lots of things. So the mere fact that bitcoin uses energy is not an argument against it. Because you yourself use and do lots of things that use up energy. Get the point? Calling it "whataboutism" doesn't challenge the point. When someone brings up the energy use it's a perfectly relevant thing to bring up that they themselves use energy all the time. Why do they do that? And why is it a bad thing in this particular case and not in all the other cases where they are in favor of using energy?

Ahh because it provides utility. Now we can get on with the argument: what is the utility of bitcoin? And why does it require energy? And is the energy expenditure worth whatever we're getting out of it? Using the logic which you dismiss as "whataboutism" we can get to the point of what the utility of bitcoin is and what role energy plays in that.