100/hr works out to around $200k/year using standard 2087 hours/year for full time work. You can get better or comparable salary as FTE + benefits. It's not much.
Well sure, because in salaried jobs no one counts your hours. However, in my experience in both finance and ad tech, you end up working more than 40 hours. My IT buddies making 250k+ work 55-60 hour weeks, easy. It's not much better in the UK, where I have also worked. When you do the math, the contractor is ahead, because that 200k figure you cited is a 40 hour week.