Why is it so important? Because, It affects whole project success.
Who should have clarity of project requirement? Every single person involved in project must have detailed information about project.
Otherwise your project will suffer from:
- Broken timelines (Client will not happy)
- Bad quality of end product(Product users never love it)
- Money and time will be wasted on feature client never need(Client will not happy)
- Client will waste good amount of time.
- In future a small change cost client double triple or may be more amount than actual amount.
- Developer never like to work with badly written code. this also force developer to write patches and make product more buggy everytime code modified.
Above are some of insights of final product.