You're competing against people more so than divisions or classifications. What is accomplishable at one club might be easier or impossible at another. It's why someone using purely local experience to draw national conclusions is usually wrong.
It's the person you're beating, not their gun. And if their gun fails then you still beat the person because they failed to have a set up that worked.
I also remember 15 years ago thinking, "who is winning at idpa nats?" and realizing at the time it was all people who also had significant uspsa experience and success. Very few pure, idpa only shooters, were winning anything big. So I thought I would cross train uspsa to improve at idpa. I realized this was kinda silly (the equipment changes today I think reduce some of that, as well as fault lines in idpa) and that I'd rather just focus on uspsa where the talent pool is indeed deeper and just everything is/was larger.