Why is my cat so skittish?

I’ve had my cat for about a year now. I got him because a friend of mine found out her cat was pregnant and she needed to find someone to take them so I did. I did not take him early so he could develop with the mom and sibling. I got him when he was around 4 months old.

My problem is he is so skittish and has been like this since I got him. I have another cat that I’ve had for almost 4 years and he is very chill he doesn’t like cuddles and kisses but he is almost the perfect cat (I deduct a point because he doesn’t let me kiss him 😂😂). I also have a pit and that took him a bit to get use to but he is fine around her now. I just don’t understand why he always seems so scared and anxious. You can see in the video he ran under the bed just from me squatting down to pet him. He is very loving and he actually does like cuddles and kisses but he gets like this and I feel so bad. My family doesn’t really have a connection to him because they think he doesn’t like them but he’s just so anxious all the time.

Is there anything I can do to curve his anxious behavior and make him feel more comfortable?