Every study done on asymptomatic carriers has show negligible differences in the confirmed cases vs those who got it and never tested. Sweden in particular thought this was the way to get there and went several months without lockdowns and distancing mandates like their Scandinavian neighbors. Their rates of cases, hospitalizations and deaths from COVID were exponentially higher than Finland and Norway. When they conducted random tests to measure how close to "herd immunity" they were, they found that only a few percentage points more people showed evidence of previous infection over those with documented positive tests.
38 million is fine. But it's, what, 11-12% of the population? And many of those overlap with the vaccinated group (they got it and later got vaccinated anyway). The threshold estimated for herd immunity is 70-75%. Even if you assumed zero overlap with the vaccinated, my point remains true - whether we get to herd immunity or not depends overwhelmingly on people getting vaccinated, on the order of 6 to 1 or more. Natural spread isn't the way.