That’s actually only true when you’re not aroused, it stretches out when you’re horny. Average unaroused vaginal depth is 2-4 inches but average aroused vaginal depth is 5-8 inches. Some people ofc have shallower, but it can also be an indication of insufficient preparation (foreplay)
As a queer girlie, I’ve never had issues w my 8 inch strap. Another thing to consider is that the vaginal depth measurement starts where the vaginal entrance is medically, not where it’s accessible. Something that’s 8 inches long usually isn’t going 8 inches deep into your vagina bcos you have stuff like labia and fupa and hips and legs and positions and whatnot
My first bf was probably 10. He couldn’t wear certain basketball shorts bcos if he got aroused it’d go down past the leg of the shorts. I never had sex w him but I felt it a couple of times and…. I think anyone would die. He’s the reason I understand those bumper-stopper things 😭 anyway he was a redneck hick who held me at gunpoint when I came out as queer