Serve and volley did not disappear, its trigger changed

What the pattern requires to work

Serving and volleying commits the server to the net before he knows what the return will be, which means the serve itself has to do most of the work. A serve that pulls the returner wide or jams him at the body produces a reply hit from a poor position, and that reply is what makes the volley playable. A serve that lands in a comfortable area gives the returner a clean strike, and the incoming server has to volley a ball travelling at him with pace.

So the pattern is not a general strategy but a specific one attached to particular serves, and using it behind the wrong serve is simply a mistake. This is the change from earlier eras, when returns were less punishing and the pattern could be used behind almost any delivery.

The first volley is meant to be awkward

A server moving forward cannot reach the net before the return arrives, so the first volley is almost always played from around the service line. That is the least favourable place to volley from, since the ball is often at or below net height and the angles available are narrow. The purpose of that volley is therefore not to win the point but to place the ball deep and buy time to take a proper net position.

Players who try to end the point from the first volley produce errors, because the shot does not offer the geometry a winning volley needs. The correct execution looks unambitious and is what makes the second volley, taken much closer to the net, straightforward.

The split step decides everything

The incoming server has to stop his forward momentum as the returner strikes the ball, or he will be moving when he needs to change direction. That split step lands at the moment of the opponent's contact, which means the server's run has to be timed to arrive at that instant. A server who is too eager arrives early and stands waiting, which loses the momentum advantage the pattern is built on.

One who is too slow is still running when the ball passes him, and he reaches the volley late and off balance. The whole pattern is therefore a timing problem more than a technical one, and it is why players who rarely practise it execute it poorly.

Using it as a threat rather than a policy

A server who comes in on every point gives the returner a fixed problem, and a good returner will solve it within a set. Using it occasionally has a different effect, because the returner must now consider it on every point and cannot commit fully to his preferred return. A returner who is standing deep to attack a serve is poorly positioned to hit the low dipping reply that beats an incoming server.

One who steps in to take the ball early can handle the incoming server but is exposed to the heavy serve he no longer has time for. The value of the pattern lies substantially in forcing that choice, which persists even in games where the server never comes in at all.

Where it fits on other surfaces

The pattern survives best on grass because the low bounce makes the passing shot harder and the returner has less time to prepare it. On slower surfaces the returner can take a full swing and dip the ball at the incoming player's feet, which turns the first volley into a defensive scramble. That is why players who use the pattern on grass frequently abandon it entirely a few weeks later on a different surface.

It also explains why the skill is maintained by relatively few players, since the return on the practice time is limited to a short part of the year. Those who keep it available treat it as a specialised tool, and the selectivity is precisely why it still works.