I freelanced (for a LONG time) for a company that had a really vile culture. Based around everyone being petrified of the MD. I never was, we got on fine - but if you showed fear, he played on it. Ultimately, very twattish, I realise.
Was 21 when I started, and was utterly stupid with it. Didn't get a contract in place (first ever freelance role) and was a bit in awe of the organisation (multimillion, biggest in their field, although very specific). Worked there for 6 years, directly with the MD, on some very sensitive projects. Eventually I grew some balls, and wanted some security - a contract, namely! They refused to even entertain signing anything, I spoke to the boss many times, to no avail, and was basically told to put up and shut up.
When DH and I wanted to buy our first house, I decided I needed some security. When I was approached elsewhere for an employed role, I took it. References came from previous freelance clients, all good.
Sent an email to the MD, copied in the chairman and directors, explaining exactly why I was leaving, and giving a weeks' notice - no contract, no problem 🤷🏻♀️
Boss was NOT HAPPY. But did enjoy telling him that this could have been avoided if he'd agreed to protect himself, as well as me. Was utterly beautiful when his chairman piled on and went bananas at him.