Superhuman has been invite only for years, apparently to be able to choose their users and grow via word of mouth. Respectfully, why is a supposedly fast amazing email experience worth paying for? I might've missed something...

It’s not worth paying for.

VCs and other high-ego executives use this purely as a status symbol.

Pretty much the same mechanism as gmail beta hype, but this costs $30 a month.

The founder of Superhuman was just on This Week in Startups and discussed their process for driving product/market fit - https://overcast.fm/+JyGzBXWg/3:25