Yes, they are uncomfortable, if your butt tries to invade the next seat. If you sit properly, with a straight back and your bum at the end (or the start?) of yo

Yes, they are uncomfortable, if your butt tries to invade the next seat. If you sit properly, with a straight back and your bum at the end (or the start?) of your seat then you can sit like this for hours. Or until you start to lose your legs crammed in the back of next seat, but that is unavoidable for tall people. People just don't know how to sit (properly), because nobody ever explained them nor they listened.