Being backed by Google should also aid it in API compatibility vs other cross platform frameworks who are always playing catchup with the native API's.
Static types, hot reloading, a solid library of widgets, native performance, "reactive" just like React.. seems like a win to me.
Regarding the points made in this post on front page today [0], I think Dart being an unsexy even "boring" language is a good thing, since it's so much like other languages new devs won't wast time with a steep learning curve.
From an evolutionary perspective this can help the platform catch on quickly.
I think if you want to make a lot of relatively small projects, web dev might be easier for a while. But as your projects start to scale up in size, having proper inheritance, compilation, a type system, etc. has growing benefits.