Teach and inspire people to become entrepreneurs on their own terms, e.g. without raising venture capital. Media company (podcast, newsletter) with a large online and in-person community.
I had the same question, but phrased as: how does it make money?
Perhaps indirectly driving people towards using Stripe's services?
That was explicitly stated at some point - more entrepreneurs, more Stripe customers. Lifting tide.
It doesn't, hence Stripe allowed it to "be indie" again. You simply do not give up ownership of cash cows.
From the post:
"Right now we're sitting at exactly $0 in MRR, so the journey is just now (re)starting."