The main thing I remember about Wing Commander 4 was it came on quite a few CDs. Something like 6? All due to the video.
I remember thinking it would make much more sense on a DVD, but I’m guessing nowhere near enough people had DVD drives at the time and it would have destroyed sales.
Interestingly enough, they actually did release a version on DVD with full MPEG-2 video (more info here: https://www.wcnews.com/news/update/13753), but it was an extremely special edition that I think only worked with hardware MPEG-2 decoders. Nowadays, you can play this version with software decoding using some community hacks, but the GOG.com version has the high quality video and has done all the work for you.
EDIT: I was partially wrong. After reading the article, there was a version that was essentially all of the CDs' data on one DVD, but that was replaced with the version I mentioned.
I had that 2nd DVD (have? will have to dig around in the shed). I played the daylights out of the earlier Wing Commander games but IV was...underwhelming despite all the hullabaloo about it being some kind of major breakthrough in interactive fiction.
It probably came bundled with a creative DVD set that included an MPEG decoding card and required some kind of video passthrough.
I remember thinking it would make much more sense on a DVD, but I’m guessing nowhere near enough people had DVD drives at the time and it would have destroyed sales.