If I use Vscode is there any reason to use TypeScript?
Vscode tsengine is able to understand js code sufficiently if you have jsconfig.json defined. It can suggest props from classes in other files, help rename symbols, it can show function params and even sometimes types. ANd if you are using external library with the ts interfaces defined it's even better.
This raises the question for my day to day work I can't think of anything MORE that I'm missing. Sure it's not as strong as IntelliJ with Java But I don't remember having fun time in intelliJ/java world either. My problems existed with a) logic b) lack of understanding of the API usage
Not having to type types actually saves me time as I iterate quickly.