You're right, no human would stack and carve rocks like this.

The folks who say "modern tools" have never used any other tools except what's in a hardware store. Power tools just save time. It's the same shit that we could do thousands of years ago by hand and determination (or elbow grease for those who build character). Machu Pichu was made by people and anyone can go visit it - the city is made of stones the size of cars all fitted together in irregular patterns and joined without mortar. If those "modern tools" folks knew masonry they would understand how incredible it is to build without mortar and have it withstand 400 years in a jungle with no maintenance.

With enough time and not enough else to do, a village can carve a mountain using sand and water. Fuck modernity. Embrace persistence.