I have not seen anyone in crypto claim that having a LinkedIn profile means that you are legit. Checking the profiles of the team members is just one of the many steps done when verifying the legitimacy of a certain project. If a team doesn't have LinkedIn, that can be seen as a sign that they are not being transparent. Take a look at the
Scam Accusation board and you will find many projects busted for having fake teams.
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.