There are better alternatives that respect user privacy and freedom, i.e. that actively encourage alternative clients instead of banning people for using them over bloated electron garbage.
We're comparing 20 unpaid volunteers (IRC, Mumble), a dozen employees of a small business (Teamspeak) to a several million dollar large VC funded team able to run at a loss (Matrix) and a couple billion dollar large VC funded team able to give away stuff they don't even have (Discord).
You can't compete with free beer. Especially not as a bunch of unpaid volunteers.
In the end, the VC money will dry up and these companies will end, as they'll either have to increase prices, reduce services or sell out their users.