Pros
You can definitely get matched with companies that are doing some really cool things. Overtime 1.5x regular pay, and depending on the company you're contracted to, could be unlimited.
Cons
You could end up being a contractor for a company for many years and never become a full-time employee (FTE). For the company I was contracted to, the people I saw who transitioned to FTEs had to make a lot of sacrifices to their work-life balance (frequently working weekends). You have to be very proactive and constantly go to them when it comes to opportunities. They will almost never initiate engagement with you when it comes to your personal growth. Even the cheapest medical insurance is very expensive 401K match is extremely low They don't approve or track PTO, the company you're contracted to does.