If we use less energy or quality of life decreases. That's true for us, and it's true for every known living thing to have ever existed.

I don't want to use less energy. In fact most don't want to and most are not going to. So instead of wishing for something people don't want to be forced on them we do what people do want in a way that is better and less detrimental.

Your not wrong, but your misrepresenting how good of a thing this is.

It would be like me being all smug years ago saying, "Yeah that solar power thing sure is cool, you can run a whole calculator with it."

And yet here we are in 2022 with solar power being a serious competing energy source for the grid.

Greed?

How about, "we can assume that technological civilizations will have noticeable byproducts of producing technology"?

Sure there could be a non ambitious primative civilization out there. But A, they probably wouldn't have evolved intelligence if they weren't going to benefit from it and B, we couldn't detect them then.

It's foolish to believe that any technological civilization doesn't have "pollution". If their home planet has non currently that simply means they moved it into space.

This fantasy that technological civilizations could both have advanced technology and stunning architecture but no byproducts is ridiculous. What did they do WILL steel beams into existence?