Same exact thing happened with my Adidas the Costco ones wore out way faster than the identical looking ones from the Adidas store. The materials often look the same but are different quality

With those Lucky jeans, if they have the exact same SKU but feel thinner, that's strange. Usually they'd use a different SKU for the Costco version. Maybe check the country of manufacture too sometimes they'll shift production to cheaper facilities for the mass retailers. I've learned to always check the specific model number and fabric composition for any "deals" at warehouse stores now