i dont think its unreasonable to scale back the timelines on these ancient megalithic structures. whats 1000, 2000, 4000, 10000, 20000+ years in the past when you still have the same basic problems of who, how and why they were built. in fact, the further back they go the more plausible some of these structures can become. then you can say, well 10k years ago they had woolly mammoths moving these things and they had a lot more time to do it. the Younger Dryas Event occurs and then construction abruptly stops due to massive extinction of megafauna and ancient peoples. lots of lost knowledge. by making these things only a few hundred years ago like say the Peruvian megaliths just makes no goddamned sense. there is a VERY clear distinction to the manner of construction.
look at this example.
this is the third pyramid in egypt. (menkaure)
roughly 4000 years old according to the narrative
then you have the megaliths in Peru
around 500 years old according to narrative. they look the same
there really needs to be a break in the hivemind and admit. yes, people have been awesome and a lot earlier than we previously imagined. Gobekli Tepe has already set the precedent.