RE: If We Lived on a Sphere, Wouldn't Buildings Appear to Lean?
In Riddler's video, there isn't near enough water to fill even a small area of those valleys. Thus in that Earth, the above sea level measurements would give some extreme readings in many regions of Earth.
Coincidentally, from the perspective of human, we would also see some bizarre anomalies in many regions. A rising horizon such as when one is at the foot of a mountain range would be a common sight. One would observe gigantic mountain ranges. From the perspective of Brazil facing towards Chile for instance.
I don't mean to discredit you nor the scientific community here. I'm merely questioning what logic determines as a clear discrepancy. Which evidently, is why the conspiracy of Flat Earth has grown in magnitude in recent years.
There ARE conflicting 'truths' within the science community and from reputable organizations, which in turn fuel speculation. Proclaimed images of Earth by NASA vs the now standardized version of a lumpy Earth alone would mean that one is a fallacy.