What are my weak spots?

I feel like my illustrations consistently are lacking some kind of charm to them and they feel unfinished. I know im not good at composition, but I dont really understand what Im doing wrong or how to get better. I cant seem to pick colors that work but I dont understand why they arent working. I try to look at my images in grayscale while Im working to check the values but I feel like it’s not clicking.

I know theres a lot of room for growth and improvement, but when I cant understand what isnt working and i just go in circles, I want to quit. I would like to have someone tell me if there is one or two things I consistently fail to do or seem like I am particularly bad at so I can focus on that rather than blindly tackle everything at once and giving up.

Brutally honest opinions and feedback is appreciated.

Thank you.