I recently learned about bookshop, and was super excited until I actually started making a wishlist of stuff I wanted and found half of it to either be back ordered or not exist in their system at all. Turns out all orders are processed through a single book supplier and if they don’t have it bookshop won’t either.

As someone who doesn’t use Amazon, I tend to use indiebound, which just pairs you with the closest independent bookstore who has the thing you want.

or alibris.com