This happens when you repeatedly cut or bite your nails very short. Yes genetics and your own nail bed plays a part but you could have bigger nails than this for sure. This is my own experience:
The skin that was hidden by the nail then hardens when you cut your nails so short it becomes exposed and dried up. so when new nail growth comes you end up, it acts like a ramp and the nail grows with a lift up too early. You end up getting a wide white stripe at the tip that starts early on the nail bed. If say it should start at 8/10 of the nail, if your nails are super short you could see the white stripe at 6/10. The white edge of a nail at the tip is separation from the nail bed. I think the skin hardening makes the nail lift higher.
The cycle of weak annoying ugly nail begins and you cut it again. But if you can bear it, let them grow with nail hardener applied daily. The first two times they grow they won't look great. Keep applying hardener and only when they are really longer ie beyond your finger tip then file them. It will take 3-6 months for your nails to get healthy and longer again.
Meanwhile you need to strengthen them from the inside with vitamin D and calcium and ideally also a skin hair and nail supplements. Supermarket own brand has the same ingredients as perfectil. Eat protein, fix any nutritional deficiencies. Iron is also a big one affecting nails.
You can push the cuticle back and it will make them longer but don't get too enthusiastic with it. I recommend getting cuticle sticks (available in shops or online), cuticle trimmer scissors and Sally Hanson cuticle remover. You will also need to apply almond oil or a hand cream frequently after washed and very importantly overnight. I also love the Neutrogena hand mask. My hands can look very dehydrated but after this mask my hands look well hydrated and very soft.
Goes without saying, don't use your nails as a tool. Carry a file with you so you tackle any annoying overhangs or file any tiny breakages before they become big.
Women with beautiful hands and feet usually spend time taking care of them especially once they're past 30 it's not a matter of luck anymore but a matter of regular care.
Make moisturizing your hands and cuticles as easy as possible.. I keep one by my bed, sink and in my bag.
So patience and upping the care.