Discord is described as 'A versatile platform for text and voice communication, featuring topic-specific channels, customizable moderation, and smooth low latency interactions' and is a leading instant messenger in the social & communications category. There are more than 100 alternatives to Discord for a variety of platforms, including Web-based, Android, iPhone, Windows and Mac apps. The best Discord alternative is Element. It's not free, so if you're looking for a free alternative, you could try Element or Mumble. Other great apps like Discord are Tox, Telegram, TeamSpeak and Matrix.
The advantage of Element for me is that it's open source. I really appreciate the fact that it's a flexible solution that isn't polluted by foreign investment and the profit rationale that is becoming increasingly prevalent in Discord. Especially since I've seen documentaries showing financial relations with Chinese companies already well known for their government ties. It's like creating a Discord ‘server’ with rooms from lots of different places ^^.