Even making low six figures doesn't seem like enough in my low to mid CoL area. It's incredibly taxing to invest yourself into the lives of two small humans while still maintaining your own life.
So yeah, people could live like pilgrims and have kids, but why? That's not the main obstacle in 2020. Societal, cultural, and economic uncertainty is far and away more of an obstacle than budgeting.
That’s why most married people with kids take a mortgage. Mortgage payments stay flat, but the actual expense goes down over time, because you pay less and less of interest and more of principal.
Plus, being stay at home with three small kids is more isolating then corona lockdown, so there is significant "dealing with frustration and routine without loosing your mind" challenge too.