Yeah it's interesting that. Russia is going to have real problems with population - particularly if it loses the war in Ukraine. There's still a cyclical lull in birthrates because of the ludicrous number of men that died in WW2.
Germany, Poland, Italy, Greece and Romania are also struggling. China's population is decreasing for the first time in decades too.
I think the predictions are that 1 in 2 babies will be born in sub Saharan Africa by 2100. Add in a bit of climate change and you've got some mind bending changes on the horizon for world populations and human migration.