Companies like this still need to be made by talented people.

I know the founder of Calm, he's extremely laid back and great to work for.

You have to believe in the vision of a company to work there and this will be no different for Calm. It'll take the right kind of mentality to succeed at a place that puts reducing stress at the forefront of its mission.

Yes, it's completely impossible that this company has its own corporate culture, they're probably exactly like every other startup (to a laughable stereotype). Working 500 hour weeks, literally paid in peanuts, and if you go on a date instead of pushing a bugfix they crucify you.