I think Discord is necessary to build a community thanks to the text channels that are really useful to make announcements, posting images/videos, or just to chat when you can't join a vocal channel, like in the bus for example. But Teamspeak is is also really useful because Discord's vocal channel are not quite as good as TS' ones. First because of the alphabetical listing, when it comes to moderate a server, it's good to have a nice listing with staff up in the channel and normal users down, unlike discord where everyone is mixed up and it's really annoying to moderate this thing. Also TS quality is better than Discord one imo, but i'm not sure if it's just me or if it's real. Also TS is better to play with unknowns people, you just give the IP, you play, he leaves the TS, while with Discord, you give a link, the guy goes to his web navigator, enter the link, click the button, and join your vocal. Sometimes you forgot to leave and the server you joined is filled with people who think it's funny to tag everyone for nothing and you irritated.
Over the last few years discord has been expanding its features to achieve multiple goals. Persoanlly, I think both are viable, Teamspeak specialises in voice communication whilst Discord specialises more on text (in my opinion). Yes Discord's voice features have been improving, however I still have many issues whilst using Discord's voice chat. Especially on phone; it can be a nightmare. I've never had an issue when using teamspeak with my communications. It does what it does well, and without flaw. Discord does a variety of tasks well, but in case (with voice), it still has a fair way to go before it's at Teamspeak's standard
