If they make voice chat require nitro, it would most likely kill the product extremely fast (my guess would be that people move to Steam, but there are other options as well). For things that voice chat is generally used (usually some kind of team based game), vast majority of people definitely don't want to limit their team mate pool to people with Nitro subscription.

Requiring certain number of nitro boosts might not be as serious, but that would likely just make people consolidate servers more (possibly split text and voice servers, but at that point they might as well consider other options for voice).

I think there is probably room for discord to sell 'premium' voice channels. Currently their stuff works /most/ of the time but is unreliable enough that a lot of people still use stuff like mumble/teamspeak.

Nitro is worth it just for the increased file size limit.

My office365 subscription is cheaper, and I get a entire terrabyte of storage. If you're willing to pay for for convenience I guess

Absolutely a convenience thing. If we're going to cost efficiency, making new Google accounts whenever you run out of free storage wins.

How do I do that these days? Every Google account appears to need a hard (non voip) phone number attached to it.

Huh. Just created an account to test it out, and I wasn't required to fill in the phone number field.

... and emoji's! (Seriously though, pretty great for bots)