It is important to know that for any project hoping to convince investors into putting their money into the project, they are going to be focused on making the project as appealing as possible which means that the project's whitepaper will surely be good so I believe you should look beyond the projects whitepaper to decide if a project is legit or not.
Always make through research of a project's team, road map and token metrics to decide which projects to invest in
Sometimes no matter how well presented a whitepaper and road maps we really cannot tell if it's a scam or not. However, base on content you can really tell if there is a potential or not.