A few years ago, but long after people'd already started praising Yarn as a superior and completely-ready replacement for npm, it was still very easy to run int

A few years ago, but long after people'd already started praising Yarn as a superior and completely-ready replacement for npm, it was still very easy to run into missing functionality if you went off the "happy path" of just installing stuff from NPM, and even then there was a decent chance of hitting bugs, often due to missing features or lack of extra safety checks that NPM was doing. Nepotism wasn't the reason the agency I was at kept starting projects with yarn (JS devs, whatcha gonna do) and pretty much always switching to NPM about the time each project was seriously getting going. It's because the likelihood of Yarn being the cause of some mysterious runtime or build bug you'd spend a couple hours chasing was at least 10x higher than NPM, or because we'd find we needed a feature Yarn didn't support. Yarn proponents have a history of pushing it despite its not being ready. Perhaps it's actually good now, though, I dunno. NPM's definitely not perfect, so there's plenty of room to improve on it.