Typescript helps you to avoid most obvious bugs(wrong classes, non-existent properties, basically to escape the undefined hell) that is the point of it, which I really like and find enormously helpful for medium-size JS project (10k-50k LoC)

Also I don't think the transpiler argument holds in today's JS ecosystem. Everything is transpiled. Unless you are developing in barebone ES5 syntax and avoid babel as a whole, then some level of transpliation is inevitable. Yet, I didn't find debugging that much difficult with correct setup.