I would argue peaking hard and crashing hard by overshooting is worse than peaking slower and then steady very long decline.
Ah, there are other possible paths. 1) Extinction (which has happened to many species) without any evolutionary successors. 2) Artificial life (it evolves without us). 3) Something else evolves (long after we are gone) and becomes the dominant species on the planet.
Humanity has limited options, but nature doesn't and we can't count on it doing us any favors.
What makes you think it's being managed properly? Fertility rate 0.78 in Korea signals uncontrollable plummet to 0. TFA: 1.2 million small businesses have owners aged about 70 with no successor, prime minister Fumio Kishida: "Our nation is on the cusp of whether it can maintain its societal functions" - sounds anything but managed properly