We've had a Costco membership on and off for over 20 years. There was a period of time where I dropped it, but picked it back up about 5 years ago. Similar to KCB, I haven't been in a Costco since the pandemic, but I order through Instacart about once a month. Even though I'm usually paying $40 for a tip, it's worth it to save 2 hours of my time and the random stuff I'd buy if I were actually in the store (plus I save gas too).
I also buy gifts from Costco and have them shipped directly to people.
Not everything is cheaper, so it's definitely worthwhile to do some research. That's especially true if you're stuck with a larger quantity than you need. I've seen a lot of products that are actually cheaper in the grocery store. Same with electronics, it's not always the cheapest. We bought our stove there. I waited for it to go on sale and we saved several hundred dollars.
Some of the products are made specifically for Costco (or other box stores) and may be slightly lower in quality, so I always consider the utility of what I'm buying. It's definitely one of the places I compare when I go to make a purchase
