There's no room for my knees, perhaps unless if I sit fully upright with zero slouch, and the person ahead isn't reclining their seat. Air travel is already ex

There's no room for my knees, perhaps unless if I sit fully upright with zero slouch, and the person ahead isn't reclining their seat. Air travel is already expensive enough. I'm not in the US. Why should I need to pay extra for something I have no control over?