Do you have an alternative suggestion? Because the ability to type "." and see what comes next, go-to-definition, find all references, rename symbol, etc. are all enormous time savers.
Just as yanis_t said, they're easily worth it even if you ignore the significant bug reduction (approximately 15%).
I don't know of any other way to get that kind of productivity boost. What would you suggest instead?
No they don't. They can make a decent guess occasionally but it's not remotely the same as in typed languages where it's accurate and works all the time.
It is absolutely a unique feature of typed languages.
Just as yanis_t said, they're easily worth it even if you ignore the significant bug reduction (approximately 15%).
I don't know of any other way to get that kind of productivity boost. What would you suggest instead?