“And it’s also, like, the white population has decreased like 30%,”
I’m going to assume this means “down 30% from the point where the population which identified as White was at its highest value”. I’m not sure where you’d find the data for this, and I don’t feel like hunting it down and doing the necessary math, but since it’s probably made up anyway, I’ll still comment.
If meant in an absolute sense, I’m 99.9% sure it would be BS. The total number of White people have probably gone down slightly, due to lowered birth rates (caused by an increase in quality of life), as well as an increased number of mixed-race children… but until the Baby Boom generation mostly dies off, you’re not going to see anywhere near a 30% drop.
If meant in a relative sense, then maybe - if you’re talking about the US. There’s been an uptick in immigration, legal and otherwise, from non-white countries (Guatemala and Honduras in particular) and the rate of “race-mixing” is somewhat higher than in Europe and Canada. I still think 30% would be an exaggeration in that case, but my intuition is off occasionally, so maybe. Europe or Canada, almost certainly not. (Unsure about Australia, New Zealand, South Africa, or anywhere else with a high White population.)
Regardless, most people have stopped caring about having lots of descendants or racial purity, and you can’t force anyone to care.