Out of everything we have today, Discord is arguably the best we've got.
Nobody cares about Skype anymore as much. VK Messenger, which is ICQ's successor, looks like trash. Telegram used to be very great but did take some morally questionable steps, yet still gives the user an awful lot of power. Zoom is garbage. Microsoft Teams is garbage. Facebook Messenger is garbage.
So if I had to pick, Discord and Telegram is the best we've got now.