That's true to a point but it depends on perspective. On a big team with a mix of experience levels, you are going to want to put up as many barriers to mistake

That's true to a point but it depends on perspective. On a big team with a mix of experience levels, you are going to want to put up as many barriers to mistakes as possible and it doesn't matter how much it slows anyone down because it can't be more than dealing with the problems will be. But less people, smaller projects, higher experience levels, and better testing are all factors that shift the balance between effort and expected return. Before TypeScript came around I wrote multiple 5-10k loc apps alone in JS and the number of bugs that TypeScript would have caught in those was pretty minimal. Working on a team of 5 on apps twice that big, I see errors that TS could catch in almost every single file.