it works [...] members seem to be more successful [...] So it seems to me that forming a freemason-like organization [...] would be an effective way to help our members achieve their goals.

That might be right, but I am not convinced. It seems to me possible that the following might be true:

• The community of freemasons has included, for historical path-dependent reasons, a whole lot of influential people.
• Fraternizing with influential people is good for your career.
• This is the dominant cause of any advantage freemasons have had.

In which case, forming a freemasonry-like organization would be valuable in that way only if it manages to recruit a lot of influential people who can help other members as freemasons (hypothetically) have helped one another. That certainly might work but I don't see that it could be guaranteed.