Earlier quoted context omitted.
I'm pretty sure that's a pretty reductive take, and if you believe that then you should be ok with decreasing birth rates as well? Every baby born today could be competition for you or your kids in ~16-30 years.
I'll bite. Quality of life in terms of natural resources available only goes down with more people. I'd be much happier with maybe 25% of current population level.
Eventually, of course, we will all have to have a neutral or negative population growth rate, but I have to believe that there's an advantage to being the last country with a growing population, though I don't have data to back that up off the top of my head.