So... what's the deal with Mastodon? Why is it becoming so popular? And should I make an account?

Title kinda says all, but Mastodon looks interesting to me... except I don't know whether I should get one. I keep hearing that it's "Twitter for saner people." I guess? I'm fine with Twitter, even if it's a bit hectic at times. But all the same: I'm just curious about the hype surrounding Mastodon.