We have seen how these guys can get balls back and back and back all damn day. Many times in both the USO and AO finals of this year, I saw many chances for guys to come into net and close with a winning volley. But they don't, retreat, and play another 10 shots
Either they are afraid of the other fellow's passing shots, or they have no confidence in their own net game or both. I think these guys need to learn to volley better, and it will save their bodies instead of playing 25 shots every single rally
It's a good point that you raise - especially in terms of adapting one's game to help ensure better longevity in their careers.
Of course a lot of the reason behind the unwillingness for players to come forward to the net (and as a result practice more and improve in that area) can be attributed to the slower courts and higher bouncing courts where the opponent has more time to wind up and hit the passing shot. It's logical that the surfaces that seem to reward coming to the net are the faster and lower bouncing surfaces - yet these are becoming rarer on the tour. But there are other factors besides this also.
When you combine today's racquet technology, improvements in players' physical fitness and the homogenisation of court speeds then that begins to paint a fuller picture. These days you really have to hit a top quality approach shot to be confident in putting away the volley - if the approach shot isn't first class then the chances are that you will be passed at the net.
I'm not saying it can't be done. But spending time on the forecourt game at the expense of the baseline is a risk that players these days seem unwilling to take. You have to remember that the slower courts reward high percentage tennis it might be a safer strategy to be consistent in baseline rallies rather than play with finer margins in trying to hit the perfect approach shot to come to the net behind.