Ideally all countries would lower their birthrate.This doesn't make sense. You think the solution to over population is to have extremely low birthrate countries lower their birthrate even farther?
You've drank the Kool-Aid. The West is short sighted and is kicking the can down the road? What, with their extreme sub-replacement birth rate?
The high birthrate areas are the only real concern.
But in any case having a low birth rate for a first world country while damaging in the short-run for economic growth is beneficial in the long run as long as you stop the immigration. Like I said labour needs will be minimal in the future once AI and robots replace a lot of jobs. Or would you rather have a large population in 30 years time with half our population sitting around unemployed receiving universal basic income?
I mean the west is kicking the can down the road by importing immigrants not by their low birth rates. The immigration is the can kicking. Just take your bitter medicine like Japan is doing.
Tech companies have minimal employees compared to the "industrial" giants of the past. Nvidia is the 3rd most valuable company in the world by market cap yet it only has around 30,000 employees. General motors has around 163,000 employees. Walmart has 2.1 million employees.
And if you have a small population the land and natural resource wealth will be spread over a smaller population meaning everyone is wealthier. Like I said look at Brunei, UAE, Qatar and Norway as good examples of this.