I'll second this. I started using Discord solely because all of the alternatives (Skype, teamspeak, mumble, google, ...) were so bad at the time. And when I say "bad" I specifically mean the UX and the quality/stability of service. Discord had good quality service and it was extremely easy for non-technical people to use, and so for me and my friends who talked online a lot, we naturally just tried it out and then stayed because it continued to be good.