From my analysis it appears Bitcoin Market is practically dead or barely used. Is this accurate/true?
If so, is there something specific that Bitcoin Market does or doesn't do that causes it to not be as popular, successful, widely used or otherwise useful as other competing markets/exchanges? What are these things? What can help to improve Bitcoin Market so that it will be more accepted or useful to others?
How did you do that kind of analysis?

Just take a look at Bitcoin on coin market cap and will answer your question.
As of now, Bitcoin dominates 53.8% of the whole cryptocurrency world and it has a trading volume of $7.3 billion
dollars with a total market capitalization of $75 billion dollars.

Bitcoin isn't dead and if Bitcoin is dead there will be zero dominance, zero market cap, and zero volumes.