If you're fully saturated with work and you're not making as much as your salary, you're probably not charging enough.

Freelancing's risk is that projects come and go, so you need higher rates compared to salaried jobs to provide more of a buffer zone for yourself.

On the other end, your clients are saving from not having to provide benefits and having efficient resourcing (both in that they can ramp up the work when needed, and the fact that if you're billing per hour, you're actually doing work as opposed to someone just hanging out at their 9-5 job)