And it is not at all uncommon.

There is a reason that, back in the day, there were a LOT of ways to compress game installs so that you could burn it to a CD-R and so forth. And this was incredibly prevalent on consoles up until the current generation when SSDs became default… except that a lot of games were still being developed for previous gen and older hardware PCs.

When Blizzard made a big deal about how WoW now requires an SSD? It was for stuff like this.