Your use of "illusion" and "pretend" seem a bit dismissive or cynical.

It's just a vinyl interface to a digital set up. The alternative (when using digital music) is a digital controller which also tries to mimic vinyl, just more poorly.

That's correct (I used to mess around with this stuff several years back). There's a bit more detail in part 1 of this series as well: https://mixxx.org/news/2021-11-21-dvs-internals-pt1/

I feel you're being dismissive but it maybe TFA would make more sense if the use case was more clear. The typical vinyl DJ setup is a pair of turntables, mixer, and PA. This adds a laptop and one or two of these encoded records to the mix (pun intended). Some signal routing between the laptop and the mixer allows your encoded records to work just like regular vinyl - you can have an analog record on one deck with digital on another, both players analog or digital or however you want to handle it. Your digital tracks just become records you can fade into the mix alongside your existing analog workflow. You mix using the regular DJ mixer, everything is almost exactly the same as using regular vinyl records except you can also have a shipping container's worth of tracks in a laptop sized format.

It's not for people who wanna play at being a vinyl DJ (there are digital control surfaces for that), it's for people who are vinyl DJs and have all that stuff and are used to using it but who would also like to occasionally dip into a larger record bag when at a show.

That compatibility can be pretty valuable as it allows you to mix between digital and analog vinyl on the fly on the same hardware. DJs of a certain age grew up around the UX of the Technics 1200s and these sorts of tools allows them to keep the feel of the instrument that they've learned to play.

A Phase DJ is $400 for a pair, compared to $80 for the Serato timecode vinyls.