> defaulting to dynamic and making static opt-in undermines a lot of the potential benefit of static typing. I don't think that it works the other way around
Yes, there's certainly truth to this. However, I write a lot of TypeScript and it provides an _exquisite_ on ramp in that you can add types gradually and telling the compiler not to worry about it can be super useful, especially if you're dealing with poorly behaved third party stubs that may have diverged from the actual implementation. The fact that you can use TypeScript as a super-duper linter _or_ try to maximally leverage its powerful type system is a huge strength. It's also very helpful for adoption. As frustrated as I get sometimes with TypeScript's unsoundness and the lack of pattern matching, the fact that I get to use it instead of JavaScript (and have also got half the company using it!) is a huge win.
Yes, there's certainly truth to this. However, I write a lot of TypeScript and it provides an _exquisite_ on ramp in that you can add types gradually and telling the compiler not to worry about it can be super useful, especially if you're dealing with poorly behaved third party stubs that may have diverged from the actual implementation. The fact that you can use TypeScript as a super-duper linter _or_ try to maximally leverage its powerful type system is a huge strength. It's also very helpful for adoption. As frustrated as I get sometimes with TypeScript's unsoundness and the lack of pattern matching, the fact that I get to use it instead of JavaScript (and have also got half the company using it!) is a huge win.