You need to understand that as a contractor clients value more than just your time and the work you do. They value flexibility in staffing, getting an outsider’s opinion, their own time, working with a true expert, and making progress on projects which they can show off to their boss.
That’s why for all my work I scope project fees plus monthly retainers. The retainers are use it or lose it. Then I focus on delivering the best possible experience for my clients.
By switching to this model I do about 3x my previous earnings. And my clients are happy (I haven’t lost one yet).
It doesn’t make sense to become a contractor just to remain a wage slave.
(Before all the “I can’t do this because my situation is different”: You are full of it. Anyone can do this.)