If you think about human languages and assume you'd have to hire developers to build up a team, you would very likely require the candidates to speak a language everyone understands. Since good communication is a key for efficient, successful software-development, it is clear that you need one language every team member understands.
But what about programming languages? Basically the same thing: If possible you would use one language to implement an application.
- arrow functions,
- spread operator for array and objects,
- optional chaining
- nullish coalescing operator
...And TypeScript! Even though I was a late adopter of TypeScript, I am very happy to use it now.
- It's easier to find developers
- Very good Community support
- Good for Artificial Intelligence (AI) and Machine Learning (ML) (huge open source community => a lot of data)
- Chance to find some libraries for your use case is higher
Although JavasScript is very capable, it can and should not be used for everything! Nevertheless, especially for user interfaces and web applications it is very likely to be an excellent choice.