It's sad that you have to be worried about downvotes for an opinion. I disagree, though. Instead of going with a lengthy list of why I think TS is great and di

It's sad that you have to be worried about downvotes for an opinion. I disagree, though. Instead of going with a lengthy list of why I think TS is great and disproving your arguments, which I assume everyone else will do, I'll admit that types can be hard, and so doing them right, or even doing them as best as one can, will always take some time. For a small project or a small team, that time might be hard to justify. But I think this is resolved with a good understanding TypeScript. Even so, TypeScript might not make sense for many projects or small teams, but I find it hard to defend that TypeScript won't be a net win for any medium team or medium-size project. This was my believe before, but I've seen multiple teams go from JS to Flow or TypeScript and the result has always been, when there's expert guidance, extremely positive. Productivity goes up, more bugs are fixed because there's more confidence in the safety of the changes, more people feel confident to work on any part of the codebase (vs just the people that originally built it or have worked more on it), and the defect rate dropped dramatically.