I don't think the reason why these languages are terser is because they are dynamic. Something that always frustrates me to no end is how many older statically types languages barely have a literal syntax.
Literal syntax and stdlib size and APIs. The latter is especially important on iterator and container interfaces. They must fit together well and be composable.
This can be exemplified using Crystal, which is close to Ruby in both terseness and APIs, but statically typed (and with static dispatch).
