languages aren’t ‘duck typed’ duck typing is to do with protocols, duck typing can be used in a language that is even statically typed.

javascript has weak types meaning they can be coerced to other types, the confusion arises because by defining a protocol for type coercion you can get weak types from duck typing.

what is a strict type?

Also there’s no reason whatsoever why a dynamically typed language cannot be strongly typed

but you also gain intellisense and auto-complete and all that too.

I don’t believe this has anything to do with types at all

I can’t tell you how many times I’ve been saved by accidentally forgetting a field that was marked as required, at compile time.

There’s no reason why an implementation of a dynamically typed language cannot check for things like this either, this is just a common misconception brought about by the way some interpreters work.