Partially true, but you need to have an above-average serve and some combination of speed and / or long reach to build your game around it IMO. It's not just a question of getting used to charging the net after every serve.
time_fly
I tend to agree with you. You must have a decent serve, something players can not tee-off on, but most important serve placement is
probably most important. You'll want to pull you opponent off the court which means hitting angles. Today you will not go to the net on
every serve because there is no surprise in hitting the same serve every time. Use the serve to pull opponents off wide and also jam the
body.
Yes, you must be fleet afoot. All players who use S&V have excellent footwork, are light on their feet, and relatively fast. There movement becomes ingrained, there is a feeling (a rhythm) to it.
As for reach, while not so important. I know a 5 foot 5 inch tall 40 plus year old ex-pro who excelled at doubles, which is not true S&V,
but doubles uses S&V technique. At 5' 5" his serve is/was just above average, however his serve accuracy is excellent. I have seen many
college players suffer in singles at his hands. This ex-pro is known for being a grinder, but he still mixes in S&V. He is short and his arms
are short, but you would be amazed how he comes to the net and knows when to come to the net. He knows how to use his tremendous
speed. Let's call him Flash. Speed makes up for short reach.
You will never be a serve and volleyer unless you practice it and find out what works and what doesn't. So, as the saying goes, "nothing ventured, nothing gained".
Aloha