The problem is consumption, not population.
There are people going around shitting out kids left right and centre and I'm treated like the antichrist for wanting some bottled water.
I agree there is probably no good reason for anyone to have more than 4 kids (at most, probably just 2 to go for a manageable population decline) but lifestyle is simply a more important aspect of the equation.
We became vegetarians the moment we became parents. Not because I think our individual change will make a difference but because I want it to be a no-brainer for our kids to drastically reduce meat intake.
If you don’t want to raise kids, that is fine. But don’t act like having 1 or 2 kids is ruining the planet. It is not, it’s the way we live that is.