I can't think of many reasons Discord "ate the whole market" besides smart marketing, honestly. It does audio rooms incredibly well, but everything else (even their developer support team) is just terrible.
Even years later it's still the only platform I know of that combines text chat rooms, voice chat rooms, and video streaming into one place, all accessible from your 'server' as they call it.
It also has clients for many platforms, including a web client, all of which look and function the same.
Any alternative out there does one of those things decently well, but either completely lacks or is utterly awful at the other things.
and unlike skype (and probably teams too) supports PUSH 2 TALK which gaming oriented voice chats had close to 2 decades ago and is even more useful now, during WFH.
The big issue they have is building up a large enough network effect. I really can't see the discord communities I am a part of moving over there any time soon. Also, they were recently acquired by roblox, and nobody knows for sure what the new ownership will end up doing to the platform.
All the features afterwards are mostly just them throwing stuff at the wall and seeing what sticks.
Ventrillo and Teamspeak and Mumble were all good. But you had to assign someone in your friend-group to manage the server. This meant paying for hosting to do it "the right way", and in turn one friend either paid the hosting themselves or you had to figure out how to split the cost. Then if someone else joined the group you had to split it with them, etc.. Some people would self-host teamspeak or ventrillo at their houses so you could avoid those costs, but now you are reliant on an unreliable system of one friend hosting your voiceserver on their desktop computer. This means that router mishaps could send it offline, them turning off their computer could send it offline, or if the teamspeak/vent daemon wasn't running then your whole server is offline.
Skype solved a lot of those problems because it was always online, no one had to manage a server, and it was free. It sucked in just about every other way as a game chat option, but the benefits of no-server-management, always-available, and no-cost, made an objectively inferior product dominate the world of game chat.
Discord simply took the features of teamspeak/mumble/ventrillo and combined it with the service benefits that skype offered. No more server cost sharing and no more server administration. But you still got the benefits of actual game chat servers like voice lobbies (as opposed to initiating calls like skype).
I really don't think Marketing is what made Discord successful. This is truly an example of someone who solved a need. We needed a product like teamspeak/ventrillo/mumble combined with a service like skype. Discord was that creation. It truly solved a problem for gamers. Gamers were not looking to cling to skype, but they were all using it. Discord created a product that fit into the market perfectly and the masses ran to it because the need was so big, and Discord solved the problem that gamers needed. The ease of setup also helped. Sending a single share link that someone simply clicked was all it took to join a server and start talking. I think that ease of setup is also an incredibly under-rated strength of Discord. In fact I would venture to guess that most gamers joined their first Discord server by clicking a discord share link that was sent to them via Skype.
The ability to easily create servers, invite users to your server, and then make that server your homebase with its own channels and emojis, is pretty novel and perfectly fit into the gaming community which is basically a loosely connected graph of friend groups.
The fact that you can:
(1) Find a server with a simple URL (no pw needed, no port or IP, etc.)
(2) Find your friends easily with a unique username and use chat as a fallback
(3) Create an audio room (that scales!) that has great audio quality (doesn't "drop" calls and
(4) Client that auto-updates to provide more and more features
All within a few minutes is a HUGE upgrade or Ventrilo.
This doesn't even mention the network effects, bot integration, gif/photo capability, etc. It's superior in almost every way possible.
Everyone I have spoken to loves discord and thinks it is one of the best programs they have. It's only a select group of hacker news style users who complain about minute details the average person does not care about.
I know it's hard for most people on this site to understand but the average user has very different priorities. Being able to create a "server" with the click of a button is worth more than every other issue listed in this thread. Having to pay or self host to create a group is a total non starter in 2021.
To say people were manipulated into using Discord is obviously not true, but it's also disingenuous to deny the massive amount of marketing Discord pushed back when it first started, not only in advertisement but just branding in general.
I'm not going to address the latter part of your comment because I don't understand what you're trying to say. I'm of the belief that I'm allowed to voice the legitimate issues I have with the software that impact not only myself and other developers but users in general.
You don't see how those valuable those improvements are but the average person does and that's why it has a massive market share.
Mumble is also self hosted, and nobody wants to host anything anymore when there's a free alternative that's good enough and hosted by someone else.
Skype is just universally terrible.
EDIT: since I'm part of that tiny minority exception that proves the rule: s/nobody wants/the vast majority do not want/
* Where the server is hosted / quality of server
* Poor client UI
User interface and end user fulfillment just aren't great generally for OSS. I think it would take a commons improvement project with either government grants (infrastructure) paying for results AND/OR a university spearheading the development project.
1) They send magic links. Pretty easy.
2) They make all known workspaces you've logged into before discoverable and allow for a one-click "add to desktop Slack" option, which makes dealing with the whole "different users" issue. And to the extent that I use different emails for different workspaces, Slack accommodates that and allows me to do so within the same desktop instance, so not really sure what the concern is there.
I despise discord quite a lot btw :)