Why? I have an open source project and we run it on Discord with 500 people on the server because it's just better than anything else available. Yes I wish there were an
open source alternative but
there isn't really when you don't want to self host or manage servers like with TS or Mumble (and those are utterly lack any contribution or chat features). Just voice chat alone doesn't cut it and Mumble not even that good as some people make it out to be
Element is the closest but the fact that it's paid already a huge turn off for a lot of users https://element.io/
Element isnt paid?
It has paid hosted options if you want your own synapse server, but the free version has always been there and if you're using discord why care that you dont have your own domain for your matrix community
On discord, communities (or as they call it servers) will typically have many different channels. From my understanding you'd need your own domain to replicate that on element. Eg. #memes:ultimatefrisbee.pt
If you run an open source project yourself, maybe you could sympathise with the contributors and formulate your criticism in a more constructive manner.
This attitude of "you got it for free so you can't complain" is a scourge on open source. How can something ever improve if we can't point out the flaws in it?
I wouldn't say so, unstructured complaining really doesn't help at all. If the project has been around for a while then the flaws are usually well known. Before you lodge a complaint, you'll want to check the bug tracker to see if something has already been discussed. If it has, then the flaws have already been pointed out, and further complaining upon that point does nothing and only serves to annoy the people working on a fix -- the best thing to do there is to start contributing and collaborating on a fix to the issue. Then once you do that, you'll see why it's not helpful when people keep bothering you with "is it fixed yet" type comments :)
Element is the closest but the fact that it's paid already a huge turn off for a lot of users https://element.io/