Filled out with the feedback I had.
I don’t really like a flat USB charger for inaccessible spaces. What I use instead are extension cords with a flat plug head, much thinner than any charger, to bring access to outlets to the space next to the bed / couch / furniture that blocks an outlet. A flat charger would need long charging cables to get out from behind a bed or couch, and if a cable falls out or is damaged somehow, you have to get back there to fix it.
I like foldable plugs for travel, but they don’t help here because being in an inaccessible space means it won’t be taken in and out often at all. And the requirements for a travel plug are a little different in general.
And USB-A isn’t on my list for anything new I buy these days, USB-C is the way to go as others have noted.
But others have very different requirements, just some of my thoughts.