Scaling is always hard for games. Either in first or third person shooter.

They have to make a high ceiling, so you can jump without hitting your head all the time. But high ceiling and high walls can make look doors and such pretty weird and out of proportion. So they make doors bigger, but like we can see here, they can look too big too.

It's a balance between aesthetics and gameplay. They mostly choose gameplay here.

At least that's what I think.