I knew/know a Mason, afaik his involvement consisted of drinking beer and fund raising for charities a few hours per month. He’s not a Shriner specifically but a lot of lodges do stuff like that.

It’s definitely an old boys network though and a bunch of them are on various chambers of commerce and own local businesses and whatnot. I’m pretty sure he became a member strictly for the business connections. If you’re in a smaller area joining a lodge can be a very solid networking opportunity.