tolgaaaltas I agree. But to add more of my point of view - they want to buy it for a reason. GitHub is used by almost every developer and many big companies, including Google. Discord has some big communities too and is more of a social media. It's not just for the money, but power and control too IMO.
They're going for monopolization, which is not good for a company that is already that big. They want to control as much sides as possible. Microsoft develops the worldwide's most used OS, has MS Teams that took over the pandemic as a formal form of communication and Skype for the less formal part, and recently GitHub for developers. And more. But what they don't have is a recognizable chat application. If they could, they'd buy Twitter, Facebook, Telegram or WhatsApp already, but they'd fail (because they're so big, their owners just don't need to sell it). The reason why they go for Discord is because it's not that big for the owners not wanting to sell it, but still being popular and recognizable. Facebook itself bought many social media (Instagram, WhatsApp, also attempted to buy Twitter once) to get rid of competition too - this is similar story.
Yes, Discord will most likely stay free because of this. They don't care about money much, they're the richest. But they want to have the power
