Gnome is great because of the large UI size. Like my 14" notebook has a roughly 2800x1600 screen resolution and it’s still pretty usable without any UI scaling. If the bars are an inch tall, you’re either using a huge TV or a screen from the garbage dump. Gnome really needs a modern system.
Security is there to make sure you’re not carrying illegal stuff, as long as that’s fine, the only time they maybe check the id is before giving you the boarding pass.
Looks like the guy didn’t have a boarding pass altogether, so not sure how he got into the plane.
There is usually a person or an automatic gate that checks your pass before allowing you through the plane. However that’s more like a ticket check and to make sure people don’t get on the wrong planes, it’s probably not super hard to get around.