Population growth is in decline in real terms [0], but as you say it will take decades, unless you advocate enforced involuntary euthenasia. Even plunging populations, as Japan is experiencing [1], brings other problems such as economic recession. We really need to stop worrying about population [2] and revisit some baseless norms of common policy, such as "trickle-down economics" and other Friedman gems that leads to rampant overconsumption and wealth concentration.

There is hope, we just need to listen to those who want a change, not those who just want to maintain their already huge asset piles.

0: https://www.ted.com/talks/hans_rosling_on_global_population_... 1: https://www.npr.org/2018/12/21/679103541/japans-population-i... 2: https://en.m.wikipedia.org/wiki/A_Modest_Proposal