Try following some projects on Discord. Maybe a small one like Leela Chess Zero. It's a completely different experience than Slack. Maybe you and your friends could be happy there but for projects with hundred/thousands of fans/developers/contributors it's in league of its own. It got it users because of it. It didn't luckily stumble into a userbase. If it disappeared today people would be sad and switch to something else if it would reappear in 2 years everyone would be switching back ASAP.