Just crossed the half-year mark since I quit my design gig at a manufacturing company to go independent, and I figured I'd share how it's actualy gone since a lot of people here helped me think it through.
The fear was that I'd only get boring one-off jobs nobody senior wanted. Reality turned out diferent but not in the way I expected. My first two clients came through an old professor and a guy I met at a trade meetup, and both were small. Then one of them referred me to a startup that needed simulation work on a housing they were redesigning, and that's where things clicked. Turns out small consultancies and startups hire freelancers for exactly the heavy math and analysis work thier staff never has time for.
The tradeoff is real though. Income is lumpy, I spend way more time chasing invoices and writing proposals than actually engineering, and there's no senior colleague to sanity-check my work. I picked up a cheap liability insurance policy before taking the first paid contract, which I almost skipped and really shouldn't have.
Would I go back to a desk checking BOMs all day? Not a chance. But freelancing is less glamorous freedom and more wearing three hats at once, so go in knowing that.