This bobbin has multiple layers of thread wound onto it. Yes, it's frugal, but have you thought about what's going to happen when one layer comes to an end or gets tangled under another layer? It may cause the needle to jerk, and put a burr on your hook and/or break a needle.
This bobbin has been wound very loosely. It won't feed evenly, and your tension will look very bad.
This bobbin has a loose thread, so instead of spinning smoothly inside the bobbin case, it will rattle and jerk and give you a bad stitch.
This bobbin also has a loose thread that got wrapped around the outside. It cannot give you a smooth stitch.
So, pay attention to the little things!