How do you overcome the "build it and they will come" trap?

I recently saw a dev tool with great architecture and test coverage sitting at ~30 users after 4 months.

It seems like a common structural issue for technical founders. We naturally bias toward optimising code and feature completeness because that's what we are good at, while treating distribution as a secondary problem to be solved "later."

For the technical founders here who successfully transitioned from engineering a product to actually distributing it, how did you force that mindset shift? Did you bring on a co-founder, or did you brute-force the marketing yourself?

(I wrote up some of my own thoughts on this on Hashnode https://istiaq.hashnode.dev/the-ideas-in-startup-ecosystem, but I'm looking for practical advice from this community).