Are you from the 1800s? Malthusianism has been discredited for decades, thanks to the green revolution and falling fertility rates. Not to mention all politicians that tried to do something (ie. didn't "ignore the problem") have a sorry track record - eugenics, one child policy, or forced sterilizations.
Infinite growth, in any form, is a fairy tale for economists.
The second is that the status quo on Earth is never sustainable. For but one example among many on this note, Earth has gone through multiple mass extinctions - long before humans arrived on the scene - and it will continue to do so; in fact we're rather overdue for one. So the idea of living in perpetual harmony with the planet sounds like a nice goal, but is itself also a fairy tale. This certainly isn't an argument to just YOLO away the Earth, but rather that doing things that are relatively self destructive for the sake of trying to achieve a perpetual harmony is unwise, because that goal is impossible to achieve.