I work with typescript everyday. I review prs, i mentor junior devs that are learning typescript. Ofcourse this is my experience, maybe yours is different, if so please tell me about it. The only thing i said is that there is an upfront cost in velocity that people are usually not considering when they are choosing to use ts over js. Sure, that cost may be amortised in fewer bugs and easier collaboration across large development teams. But i see people struggling everyday with specifying correct and complete types. I reject prs, i babysit devs that can't figure out how to type certain code constructs. And if i don't do this the project ends up a mess of anys and ts-ignores which undermines the value proposition of typescript.