I'd hard argue
I've been using various VoIPs / Voice apps over last 15 years almost everyday - ventrilo, teamspeak, mumble, skype and I must say that Discord is unparalleled.
It fucking eats competition by it's quality, design and technology (API, BOTS). It offers also some kind of innovation because none of those most popular VoIPs / Voice apps combined Voice+Chat+Screen Streaming!
Things like Skype, MS Teams and probably similar CANNOT EVEN IMPLEMENT BASIC FEATURE LIKE PUSH 2 TALK THAT VENTRILO (or software that's aware of gaming users) HAD LIKE 15 OR MORE YEARS AGO https://news.ycombinator.com/item?id=24429842
So how is it that "No one wants to buy the actual chat application itself, because they could build equivalent technology on their own." yet nobody can some with something that's even cloes to Discord?