#4: Do you automatically update the cart when shoppers change the quantity of any item?
If you don't do that, each time when someone wants to change the quantity, they will have to click on "Update cart" button, which is actually unnecessary if you have automatic updates.

"Edit cart" and "Update cart" buttons are just examples of bad UX of shopping carts where users have to make unnecessary actions.
Instead of that, set automatic updates when users change the quantity of items (write certain number in quantity field or engage with increase/decrease buttons) and remove all these unnecessary and distracting "Edit cart" and "Update cart" buttons.

You can see how automatic updates works on Casper website after adding a product to cart and then changing quantity in the cart -

How to update the cart automatically after quantity changes:
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