He’s probably right, even a lot of top composers and producers only have one computer. That will be the majoirty of users… And as stated, people who do need that have probably already found alternatives - VEP, MIDI sync over LAN, or Cubase System Link.
I guess the benefit to server, is, you wouldn’t need to buy multiple instances of the program or? I’m not sure how that works. But, it’s likely such a niche a thing especially as computers are so powerful. You can pretty much build a single computer if you spec it right - mind you, that could be upwards of $10k.