There's free 2-day shipping from Costco for purchases over $75 (at least in Seattle). It's not hard meet that requirement. Right now, I only tend to go to Costco if I need to buy refrigerated or frozen items.
“costco delivery” is basically amazon with a higher minimum spend and no perishables. “costco same day” is delivery costco via instacart, with adjusted prices. i use costco delivery a lot because a good portion of what i buy there can be delivered with it