There was a major upgrade to the conference calling about 6 months ago which took it from being "barely usable" to "almost as good as Zoom". It's different semantics to Discord in that it's classic conferencing rather than a voice channel, but it works well enough for the whole core Matrix team to use it basically constantly for remote collaboration.

The conferencing servers are currently in London however, so you may suffer from transatlantic traffic problems if you are elsewhere in the world.