What’s the point of “build in public” if nobody’s watching?

Everywhere I look, people say “build in public” to grow your product and audience. Sounds great… except when you’re starting from zero and literally nobody cares yet. From what I’ve figured out, it’s less about getting likes right now and more about leaving a trail, progress updates, decisions you’ve made, even mistakes. Most of it will get ignored in the moment, but it builds a record that people can stumble on later. Also, “public” doesn’t have to mean blasting it to Twitter. It could be small niche communities, Reddit threads like this, or a tiny newsletter. Basically, don’t measure it by immediate engagement. Think of it as planting seeds for your future self. Anyone here actually started with no audience and made “build in public” work? What did you do?