As a former C# guy who moved to the web, I can say with confidence this is true: TypeScript is a great language for building great web apps.

My "Show HN" submission yesterday[0], the web app for helping homeless youth find beds and shelter[1], is written in TypeScript.

[0]: https://news.ycombinator.com/item?id=8886588

[1]: http://ysnmn.org