You can consume multiple bowls of popcorn discussing the difference between attaching & friction. You will find the LRI, Head Ref, & FTA don't have a lot of time for popcorn during a competition.
. Their concern will be does it meet their understanding of the rules? Will it potently damage the field.
Anyway in simplistic terms, Friction can be thought of as little ridges on one piece interacting with little ridges on the other piece. With a tangent force, the ridges try to push the pieces away from each other. This counteracted by the normal force pushing the pieces together. At some percentage of the normal force, COF, the pieces will begin to move. Whether or not there is damage to the material depends on the strength of the material, geometry of the rigdes, etc. With Velcro, the tangent force is largely independent of the normal force so clearly something is going on besides friction. All of this is done in a theoretical frictionless physics lab of course.