Dart created a lot of interest at the time. The main reason it didn't take off was that Google couldn't convince MS or Mozilla to embed the DartVM in the browse

Dart created a lot of interest at the time. The main reason it didn't take off was that Google couldn't convince MS or Mozilla to embed the DartVM in the browser. Golang obviously didn't have that constraint, it didn't depend on any external runtime. After the browser rebuff Google had a meandering approach to figuring out where Dart could fit in instead. Whereas Go slotted quite easily into one specific niche, building microservices at Google. I think the lesson is that clear positioning is crucial