This 100%. Calling is also super iffy in my experience (element / schildichat), and group calls are a non-starter, since it outsources them to a separate service, jitsi, embedded inside the element client.
Spacebar.chat (or github here) is meant to be a drop-in replacement with support for discord bots, but it has been super alpha the few times I've tried it. Haven't checked in for a few months though!
(Edit: yeah I just checked and spacebar is still very much a work in progress. Looks extremely promising though!! It seems there are devs posting updates on the main spacebar instance, which is cool)
Rocket.chat also has a self hostable option, but I don't recall that one being super great either.
It has had one, TeamSpeak 5 and now they are adding screen-sharing with TeamSpeak 6. I think they would have held a good market if they worked on an upgrade sooner, they only released a beta for TS5 once Discord had gotten super popular. If they were more proactive I think most of us would be using TeamSpeak instead now. It's just borderline impossible to convince people to move service.
Id swap but it's not comparable yet sadly. Hopefully ts6server is released soon.
Sadly I won't get to use it as my friends won't swap unless the mobile app works well. If the ts3 app works together with a ts6 server. Maybe.