Players expect characters to turn on a dime, run at a hundred miles an hour, and never trip and fall.

Meanwhile, they expect clothing to keep up, legs to stay attached, and hair to not go flying backwards like a wind tunnel.

Games that simulate actual, physical, limits of human body movement, can avoid “jank” in various points, but compared to a “gamey” game, the movement will feel absolutely leaden, slow, and plodding. Reviewers everywhere would pan the game, and, honestly, those games generally don't feel as fun as the hyper-driven games.

So, game developers have to add a bunch of hacks to cover up the fact that what they're simulating is physically … improbable. And sometimes, those hacks fail to properly cover up certain edge cases. I can guarantee that an animator and a character control programmer has spent weeks on the main character in any non-indie third person game you will buy and play on a console or PC. What you're seeing is the best they could achieve, given all the contradictory requirements that are put on character movement in a typical game.