I'll add a 4th thing to his list based on my experience moving from Java to Typescript:
Nominally-based type systems like Java (where you can only write Foo f = new Bar() if Bar has Foo somewhere up it's static type chain or interface hierarchy) are way more of a pain in the ass than structurally-based type systems like TypeScript (where you can say f: Foo = new Bar() as long as TypeScript determines Bar has all the required fields of Foo).
Primarily this makes refactoring much easier because you don't have to necessarily change things up a (potentially brittle) type hierarchy. Instead, you can just add new properties to your type to fulfill the set of properties required on the target type.
Nominally-based type systems like Java (where you can only write Foo f = new Bar() if Bar has Foo somewhere up it's static type chain or interface hierarchy) are way more of a pain in the ass than structurally-based type systems like TypeScript (where you can say f: Foo = new Bar() as long as TypeScript determines Bar has all the required fields of Foo).
Primarily this makes refactoring much easier because you don't have to necessarily change things up a (potentially brittle) type hierarchy. Instead, you can just add new properties to your type to fulfill the set of properties required on the target type.