Re: Why players don't go to net more often?
Drop shot needs to be 80% perfect to have a winning possibility, all the rest is an invitation for the opponent.
The only way to raise the number of volleys is to play S&V and chip and charge actually, as the rest of the time you -
either hit winners following your good serve
either you are defending behind your return.
Players still do some 10-20 volleys in a 3 setter in average, so everything above this is either S&V or C&C.
Both are suicidal strategies and could be used once in a while to surprise the opponent.