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