I gave up my Costco membership this last year. Now I exclusively use Walmart (home delivery) and Amazon for my household staples and I have a very good grocery store nearby for fresh products.
Costco became a burden for me although I did often buy items from them online.
As another household of three, including the two dogs, it was too much of a hassle to shop there, pack it all in the car, then unpack and put away everything....and the quantities are just too large for most things.
I don't miss it much although there are a few items that I could only get from them.
What I do miss is their meat and seafood and Parm.