Whitepaper and road mad are nice and good things for a project. They tell you what is to be expected of in project especially if you are an investor. But then scam issues sprung up, recognizing the power and influence of whitepaper and road, came in and capitalised on it to defraud a lot of investors
And now it becomes difficult to trust whitepaper and road map, but it wasn't like that from the beginning.
The solution I presume now; lets take whitepaper to tell us what the project devs aim to achieve; dont use whitepaper as a reason for investment.
White paper is just a declaration of intent of the project developers. The roadmap is an approximate timeline for the implementation of the planned stages of the project.
As my experience shows, these documents are, as a rule, followed and executed rarely and changes are often made there.
If you scrutinize closely the available whitepaper and roadmap for each project launched, you will easily identify who is putting their time and effort on creating such document. If you will see only few pages with very generic content, the probability that a project is done in a rush manner is very high. It has high likelihood that they will not develop their platform. Whereas, a project with serious intent will give you a detailed whitepaper and very comprehensive items on their roadmap. They will answer your questions in a satisfactory manner as well, because they know what they are doing.
But if you see a roadmap discussing only the creation of wallets, listing in exchanges, listing in ranking sites, marketing - high chance that this will be another pump and dump story, or just dumping of dev's coins. Stay away from this type of project.