Yes, I do think it's a good way, at least for intermediate technical roles. The amount I learned building a side project was staggering. I felt so invested in getting to good solutions and had so little technical debt fettering me that I learned 24/7. My knowledge grew more with this project than it did in college + three years of post-college work.
I built Streamus (https://github.com/MeoMix/StreamusChromeExtension). It was a Google Chrome Extension that turned YouTube into a tab-free music player/playlister. It grew to 300k MAU by advertising organically through Reddit (https://www.reddit.com/r/Music/comments/2sypcn/seven_months_...)
I ended up becoming part of the Backbone Marionette organization on GitHub (they were the frontend framework I used to build it prior to React existing), I learned how to write, manage, and scale a full-stack application, and being able to cite the success of this project kept doors wide open for me when applying to future employers.
My next job after Streamus was joining a remote, profitable, bootstrapped startup with a team of ~40 people, had equity the company, and the company sold for 9 figures half a decade later.
A++, would do again in a heartbeat, no regrets - even though the project itself was shut down by YouTube's lawyers once it grew popular enough.