Very fun and easy to use, however be careful.
Hey there people who are reading this. So, I think Discord is very good for teen/kid gamers (and others) aged 10+. Most communities that you can join are 110% safe, as I can confirm. (I am part of over 80 discord servers, and none of them have caused me any harm.). The issue is, some servers you need to be very careful with. They can do giveaways of "Paypal £10." After winning the giveaway most people just ask for your paypal support link (This is completely safe to use) However, some ask for your full paypal details which is NOT SAFE.
Also, most communities include minor amounts of swearing to some extend, however some allow swearing all the time, so be careful where you join.
Some communities contain NSFW (18+ Content) however it is Locked off unless you confirm you are of a legal age to view it (18+). This makes sure that kids are not viewing 18+ content when they don't mean to.
I myself, own a discord server that has a team of moderators that keep the server in check. They make sure the entire server is following the rules at all times and if they break one, they get a warning or get kicked (removed but can rejoin) or banned (cannot rejoin unless unbanned)
Overall, discord is safe as long as you join the right servers.