Except MoPaQ weren't zips IIRC, they had their own clever format here - at least the OG StarCraft / SCBW MoPaQs were, playing with that is what I learned binary data handling on :). The idea of zipping data files applies, of course (and many a game used a literal ZIP with custom extension).
But there's one material difference between StarCraft/Warcraft and Gimp: in Blizzard games, those were "zips" of heavy data files, notably read only data blobs. The game would read them, unpack in memory, and serve appropriately. Most of that data was key-value, text resources, or flat assets - images, sfx. With Gimp, we're talking highly structured data that's continuously being mutated. Very much not the best representation for that, even if you're just persisting it. They're only getting away with this because of SSDs - on spinning rust, you'd feel this.
(Also worth noting that, at least in StarCraft/SCBW, most of the files inside were custom, well-optimized binary formats. This predated the XML insanity of encoding data with 90%+ markup overhead.)
> Except MoPaQ weren't zips
I meant zipping colloquially as in compressing an archive format. But you seem to get the gist of it ;)
> in Blizzard games, those were "zips" of heavy data files, notably read only data blobs. The game would read them, unpack in memory, and serve appropriately.
Not just game files but also the map format for Warcraft 3 was a glorified MPQ (source: https://867380699.github.io/blog/2019/05/09/W3X_Files_Format).
So whenever you edited a WC3 map, you were zipping the current map into an archive. Much like the GIMP example. Of course, WC3 didn't use as many XML files, though SC2 changed that.