To me it's worth it because as opposed to languages designed to be strictly statically typed, the type system is there to serve you, not the other way around. It's pragmatic and tailor made for its use case.
People who've always programmed in traditional statically typed languages like Java scratch their heads on why would anyone not want to have static typing, but the reason for that is simple: in a dynamically typed language you can (and often do) produce code that's hard or impossible to type in said statically typed languages.
TypeScript's designers recognized this, so not only there are escape hatches here and there, but also the type system over time evolved to adapt to the real-life use cases instead of imposing some abstract, complex type system which might not even be very useful when used against all the creative ways JS programmers write their code.
People who've always programmed in traditional statically typed languages like Java scratch their heads on why would anyone not want to have static typing, but the reason for that is simple: in a dynamically typed language you can (and often do) produce code that's hard or impossible to type in said statically typed languages.
TypeScript's designers recognized this, so not only there are escape hatches here and there, but also the type system over time evolved to adapt to the real-life use cases instead of imposing some abstract, complex type system which might not even be very useful when used against all the creative ways JS programmers write their code.
And it works.