I've don't need to "go under my car" to confirm that you're wrong, I've been under my car because I installed all of those parts. The LCA's do not slide backward on the pins. This is because my strut rods are the correct length, and the strut rods are what locate the LCA. That's how it works.
When an OEM bushing tears, the pivot pin flops around radially inside the LCA shell. That's why the car wanders, because the LCA is now moving all over the place. That is not at all what happens with a poly bushing. Properly installed, the LCA pivot is tight in the poly bushing which is tight in the outer bushing shell, so there's no radial slop like with a torn rubber bushing. If the poly bushing has been installed with proper length strut rods, it doesn't slide back either. So you get none of the problems of a failed rubber bushing, that's just not how it works.
.