Yes, there is absolutely a difference. And yes, loose vagina is worse.
I'm no biologist, but my perception is that the baseline is set by hip width (wider hips --> more loose) but much more important is physical fitness. Strengthening the diaphragm, core, and pelvic floor quickly elevates the experience and makes the baseline irrelevant.
My ex had crazy wide hips, never exercised, but was so tight it hurt us both.
Maybe what you're saying is still true generally, just wanted to throw my experience out there.
Outside diameter has nothing to do with interior diameter, that's not how that works. The whole "childbearing hips" idea is a myth, slender women in general have an easier time with pregnancy and birth. But also tight isn't always bone structure at all. Vaginismus is overly tight muscles, or the skin can be tight (that's what I had and it sucked) or being not turned on will make anyone seem tight because not open or slippery.