Because real-life populations are, of course, not infinitely large, why is the Hardy-Weinberg condition of an "infinitely large population" usually met for natural populations?

The Hardy-Weinberg condition of an "infinitely large population" is usually met for natural populations because most natural populations are large enough to approximate an infinitely large population. This means that genetic drift, which is the change in allele frequencies due to random sampling, is minimized in natural populations. Additionally, natural populations often have high levels of gene flow, which is the movement of alleles between populations, further reducing the impact of genetic drift. Therefore, while natural populations are not truly infinitely large, they are often large enough to meet the Hardy-Weinberg condition and maintain genetic equilibrium.