Most of the things that the big Surf brands make are not useful for the actual act of Surfing. Even boardshorts from the major boardshort companies, about half their range can't be worn surfing. They're made from non-stretch fabric and intended to be worn around on the street.
Google up a "surf shop" in a big coastal town, pick the biggest, most obvious one, and chances are you wouldn't be able to equip yourself to go surfing with the things you can buy there. It'll be wall to wall boardshorts and hoodies, with a hundred pairs of sunglasses along the wall and maybe half a dozen shiny new boards stood up in a corner for decorative purposes. Observe the looks the staff will give each other if you try to ring one of those up.
If you want to go surfing, you need to find the little hole-in-the wall shop off the beach a ways, which will be stuffed full of wetsuits and boards, to the point where you can hardly walk around without knocking half the store down. They'll also have a few hundred pairs of boardshorts there, but surprisingly these ones will all have stretchy fabric and crotches that don't tear apart if you sink to your knees.
The Big Surf Brands know that most of their business comes from selling sunglasses and flip flops to people who want to look like surfers. And they're doing fine.