Not sure about now, but back then Teamspeak meant installing an application, setting it all up, having someone in the Free Company (almost always more than the limit for a free server on TS at the time) pay for a server or self-host (even more friction). With Discord there was no debate or decisions, just one step: Click link, sign up.
Same reason Zoom quickly took over video chat. It was so easy to use that you didn't have to convince your friends to sign up for it, you just sent them a link and it just worked.
It's not quite so easy anymore, partly because when you reach a certain size, it's all about controlling bots and whatnot.
I bet there’s even one related to using the word literally as hyperbole…
Zoom, in 2025, still makes you wait for the host to figure out which of the 30 other people has a dog incessantly barking or is causing the echo or has horrible feedback, and then try to talk them through fixing it before finally muting them.
I mean, what do you want, it's only been around for 50 years.
And during a downturn the high touch services lose customers faster because part of the virtue signaling of cost cutting is choosing cheaper options that take a bit more work.
Then there's the many contraindications e.g. privacy policy, walled garden, and the dog shit internal indexing and the fact that it isn't externally indexed, there's a lot of pertinent information on there from skilled individuals that could serve society a la the BBS era that will never be surfaced again because it's now being posted to Discord, though that's tangential. I hate it, but it's easy enough to use, though negligibly dofferent compared to Skype, which had many of the same issues.
I think the biggest attractor for my friends was being able to idle in a server so it was easy to start a party vs starting a call on Skype which requires a little more arrangement. Lower cost less friction.
I don't remember marketing, though.
In discord, a thread becomes a big visible thing in the sidebar. More than a couple and you're annoying everyone on the whole server. Completely the opposite of what I want.
Just funny to find myself knowing I've got this wrong before and being annoyed at myself _and_ at them
1. Its free functionality was more generous than many comparable services. Nobody wants to pay for a Mumble server.
2. Its UI and audio quality and noise cancellation settings put much of the competition to shame.
3. Only needing one account for every Discord server in existance gave it the same kind of appeal that let Reddit/Facebook kill off most individual forums.
4. Good marketing, which gave it the critical mass of users and hobby groups that it needed to succeed initially and now make it harder to move away from.