The number of words is the basic requirement of a qualified paper. If the number of words in the thesis is not enough, then the "thesis" single subject will generally fail.

If you feel that the number of words is still not enough, you should pay attention to the outline of the paper, and it is best to stroke the outline of the paper again, so that you can have a new understanding of your own topic and see if you can increase it at all levels that need to be discussed, so that you can increase the number of words without moving other structures of the paper.