What do you just think and how do you guys verify someone is legit, say if you want to collaborate/invest in their project?
It's different for every individual. Checking if the information provided in the profile is true is probably the first step.
Not just any single information, it must be accurate and legit. Sometimes, they're just using other pictures, information and people to fake their projects. It's the hardest part of trusting a project, the first step 'cause you need to check all of the social media accounts to count it as a proof or assurance for participating in that project. You can also check the contact details to verify the legitimacy of their project. There are many ways but still, it will not give you 100% assurance that they're legit.