With $1k MRR you can move to many cheap countries in the world and live there comfortably while working on your product, service, whatever it is you are offering. You can't do that with a regular job.
(And that's obviously ignoring other costs, which might not be monthly. e.g. supplies, hardware, domain-name registration, etc.)
Of course the hope is that costs fall, and don't scale linearly with revenue. Allowing actual profit in the future.