I disagree. We are already seeing the results of aging population. here is a report from stats Canada about it: https://www150.statcan.gc.ca/n1/daily-quotidien/220427/dq220427a-eng.htm
I think many economists point to the fact that western countries need younger workers to help pay for the growing percentage of the population that will be retired and needing more government services. So population increase at the rate we have may be needed even with some of the negatives it brings.
Publicly it is their religion, in private business deals they make sure the rules are set for themselves.