I find it hard to believe that every indie hacker who built a successful macOS app/cron runner/uptime monitor--had to go through calling people and asking if they need a habit tracker.

Sure, they might have been active in online communities and "spammed" their app very time someone was looking for a habit tracker, but it's far from cold calling and talking with customers 6 days a week.

I understand that all niches are different. And from what you shared, it seems like you are in a big B2B business, which I believe requires more cold calling. But not everyone is doing consulting or building for big businesses. There are people, here and on other social networks, who build simple SaaS tools or macOS apps that can make a decent living off them.