There is evidence of life from the Paleozoic era. There are footprints where dinosaurs crossed mud flats. I find it implausible that an advanced civilization that could ~ ‘go where ever they wanted’ would not leave any trace. I am also unconvinced that beings that “…just left Earth for their own reasons.” Would only leave behind dry stone construction. And as far as all megalithic structures being identical, how many different ways are there to stack rocks so that they don’t fall down?
Well, you are completely in thrall to the consensus thinking that prevails modern sciences. All your points have been answered many times elsewhere, so there is no need for me to regurgitate them here.