Binder denting and warping can occur if you have too many pages in a binder and the pages slide over the rings.
If you want to display cards in binders, try stretching a rubber band across the rings (wrapping the band around the middle ring) to help keep your pages from sliding over the rings and damaging your cards.
A lot of collectors don’t like using binders, but I think it’s a great way to display cards, focus your collection, and spend more time with your cards. Like all storage/display methods, you just have to do it the right way—always use high-quality pages (I recommend Ultra Pro Platinum Series), D-ring binders, and penny sleeves (I actually use thicker TCG card protectors because their sturdier).