Yeah people who eat beef are actually healthier than vegetarians.
Most people attribute this difference to the GDP/capita ($89,600 vs. $12,132 PPP) or the number of doctors per capita (36.082 vs. 7.265 per 10k), not the diet.
But agreed that diet is also not the only link to longevity. Although a Mediterranean diet is higher on plant based foods, considered healthier, and those countries do have better life expectancy than USA.