The US has been wavering between 16% and 15% for about a decade which is when I started taking an interest in this stuff. It's a fairly steady state.

My country has risen from 25% to 27% first generation migrants in that timeframe.

Per capita is a much more useful for comparing effects on total workforce etc.

It's not necessarily good or bad per se. I think there are so many variables at play, everything from type of migration, underlying birth rate of host country through to effect on housing stock and whether taxes and infrastructure can keep pace.

But yeah Biden's speech was just strange given that context.