Its a very thin layer of leather on the outside and very thin layers of fabric on the inside. It is 2 credit cards tall, so depending on how many cards you have, you distribute them across 4 pockets. The billfold section is split into a shallow and a deep compartment, so you can arrange things at 2 levels, if you want. I rarely carry cash, so that part usually just has some small notes or receipts or nothing at all.
So it is partly the layout and partly the materials that keeps it thin. “Nice” wallets are usually all leather or mostly leather, which makes them much thicker and tri-folds are the worst.
I don’t think the loading screens are the failure, the fast travel system is. Depending on where you are and where you’re going, you have different fast travel options. Sometimes you can pick your end destination directly (sort of). Other times you have to pick your planet (loading screen), land (loading screen), either run to your destination or pick a fast travel location on the local map (loading screen), enter a building (loading screen), take an elevator (loading screen) and now you’ve arrived. This is about the worst case I can think of with 5 loading screens.
Even in a best case scenario, like having the option to directly travel back to the lodge, you still have travel to the outside of the lodge (loading screen) and enter the lodge (loading screen). So, in most cases you’ll have between 2 and 5 loading screens unless you’re just traveling between outdoor locations on the same planet.
Which I guess takes us a step further and suggests that the pointless spaceflight feature of the game (or the pointless smuggling) is the real culprit. If you didn’t need to scan ships for contraband, they could have built a more robust map system that allowed better point to point fast travel. You’d still run into issues of indoor/outdoor, or indoors with multiple areas, but it would have been much better.