your mortgage numbers are way higher than reality. another concern is property taxes, but even at 2.5M, that's less than 30k/year in property taxes -- a working power couple or one single high earner can easily pay that. and in 20 years, 30k/year will have less than half the real value.
i think someone leveraging themselves into a 5-figure/month mortgage is the exception, not the rule.
tl;dr people are rich these days. my real concern is social unrest because of these insane imbalances in wealth distribution.