I’m not a professional, so I can’t say what exactly it is lacking to reach that level. But Some of the details look a little to smooth. He’s some kind of creature made out of wood, so I think some rougher edges might help with that. I guess what I am saying is he looks too clean and smooth. Additionally you might want to consider doing some drawings of your own of the character. The reference is cool and all, but I think trying to draw Front/Back/Side T-pose of the character would help.
Alot of the time for me, whenever I notice my work isn’t as good as I want it to be, i go back and do more planning and then I can bring it to where it looks pretty good.
One thing that sticks out for me is the face. In the reference the smile is kind of menacing, but in the model the smile seems kind of goofy. I don’t know how you’d go about fixing this, besides just drawing the face on paper to get a better idea of what you want it to look like.
Like I said, I am not a professional, but I do think most professionals typically have a fair amount of reference work from the Concept Art department when working on these models. It is the Concept Artist’s job to make sure the modelers have ALL the information for the subject matter in question.
This last bit may be bad advice, but when I “finish” a piece of artwork and it doesnt feel right, I sometimes start over completely. Rather than trying to push and pull what has already had hours and hours put into it, it seems better to take everything I learned from the piece I finished by didn’t like and start over. I can usually get to where I was before quicker.
Also, keep at it! In my brief experience with art, it only gets better. You can do it, it might take longer than you want it to, but you can do it. Goodluck!