I think it's more problematic that these parts are not done "like usual". I know I got pranked by it not once but twice.
For me, for at least 2 decades, it was always a one, continuous archive that is split into multiple files. You extract one, it will try to extract the rest. You mess up one, you won't be able to extract shit till you fix it.
I don't remember the last time (if ever) when someone did splitting OF ONE ENTITY (a game in this case) by literally making separate archives that don't "call" for one another and still calls it "parts". It makes sense for a tv series or some art collection but not here xD
I don't follow you, its always been done this way.
The game is not one big file. It's (mostly) many multiple small files so the most efficient distro method is to pack full files into separate archives or parts in this case. Only in
some cases will a single file be split between two archives if it surpasses a certain size threshold, and that's up to the tool to decide how that's done, not the user.
Whether you have a starting root zip/rar that searches and extracts the other parts (.r001, .r002) or a self-extracting archive (rar-exe) is irrelevant because within each zip are still the uniquely separated files.
It NEVER makes sense to combine a single application into single archive, then divide that archive into parts though a lot of idiots did that back in the early 2000s. Under no circumstances should anyone ever ZIP a ZIP. Or RAR a RAR, that's just stupid and doesn't save any byte space, and actually increases the possibility of file corruption.
At one point there was a guy in here lobbying for torrenting the game but I'm personally against that because torrent files are socially persistent not easy to deprecate when there's a new version, so we'd end up getting a flurry of posts of people saying "I downloaded version 1.0 and nobody is seeding" - "Well that's because we're on version 10 now dufus! Scroll through the thread and find it!" - Not to mention the fact that free file storage like Mega/GoFile/Pixeldrain is more plentiful and torrenting is being more closely monitored by ISPs (at least here in the states).