I don't think that tells you anything without comparing to the infinitude of composites too. The fraction of numbers less than n that are prime is roughly 1/lo

I don't think that tells you anything without comparing to the infinitude of composites too. The fraction of numbers less than n that are prime is roughly 1/logn, which goes to zero in the limit. So I think the limit of numbers with factors less than n as n goes to infinity must indeed be 100%. That doesn't mean there's an n with 100%, just that there's no smaller limit that some n doesn't exceed.