For instance, Discord shouldn't be a thing since IRC exists, but Discord exists and is very successful.
IRC lacks a massive amount of features that discord users typically want. Screensharing, VCs with group and camera support, built-in history (don't need to use a bouncer like on IRC), built-in online GIF searcher and sender with one click, huge community of bots that use discord's API to do anything from games to moderation.
It isn't even close.
What a lot of people don't know is that the XZ attack entirely relied on binary blobs: Partially in the repo as binary test files, and partially in only the github release (binary).
If someone actually built it from source, they weren't vulnerable. So contrary to some, it wasn't a vulnerability that was in plain view that somehow passed volunteer review.
This is why allowing binary data in open-source repos should be heavily frowned upon.