A 140grn pill in 6.5mm has an SD of .287, and out to 500 it'll hit above 2,000fps... Why wouldn't it be a hammer?

But - there's a handful of cartridges which will do the exact same, or more, even in a short action. Popularity for the 6.5 is deserved, just not at this scale. The magnitude of its popularity isn't pixie dust, it's marketing.