I read your article on freelance designers. But there was no contribution from a freelance.
Recruitment agencies play a role similar to an estate agent; their interest is their percentage.
I have never been one who just “does a job”. I take on the complete job, from client brief to delivery of the finished item. The kind of freelance who uses an agency is more inclined to be “just doing a job”, because freelancing is about commitment to doing a job for a client rather than doing a job for an intermediary.