Building open source comes with a bunch of technical benefits like my co-founder mentions, and I don't think the recent trend is a result of YC startups "running out of ideas". It's somewhat like food companies going organic - at first organic food was a special thing, but organic food is becoming increasingly common because every company is doing it. (or maybe it's just at my grocery store :) )

We decided to go open source quite naturally for the benefits that Alexander mentions, but we are also aware of the business benefits that OSS brings. Open source/open core is increasingly becoming a standard in the devtool world and as the other comment points out, there is a certain degree of natural selection at play. To gain traction as a devtool company and drive bottoms-up growth, building in public helps tremendously these days, because developers almost don't want to use closed source products. Although the rise of "open core" and commercial open source projects does come with a bit of tension with open source purist ideology, I think this trend is something we should welcome as an industry. But this trend definitely isn't just a result of running out of ideas like Disney's endless real life remakes :)