You’re also forgetting that for the last several years there weren’t a lot of factory loads out there for 6.5PRC and the most popular one has had marginal performance on game.
I didn’t really touch on long range hunting but as someone who’s got a fair bit of experience slinging lead a long way I have no issues with it IF one has the experience (thousands of rounds and a lot of time), skill (from experience and education), and equipment (takes dollars and education) to make those shots. If one has a really knowledgeable spotter and a little experience/skill one can reduce the experience but their effective range is going to be reduced a lot further than the spotters is.
There used to be a chart publicized in Hunter Ed showing what was considered the minimum KE required for each species (irregardless of distance) for an ethical kill. Me personally, I love being close because it tests one skill set, but I also love extreme long range because it tests another skill of mine. Every hunting location and situation is different. As @hatfield
pointed out, velocity and mass = energy, and most non magnum calibers don’t have it after 500 yards. There are a few exceptions but theyre ones utilizing specialized equipment to include specific bullets and most of the commercially loaded stuff isn’t it.