Are Recruitment agencies finished?

Sent a bulk email to my list of agents (compiled over 15 years) this morning. "Hi, hope all good. Might be free come Sept so just checking in" etc).

Lots of bouncebacks - recruiters no longer at the company.

Lots of mail not delivered - companies no longer exist / taken over / merged.

Very few responses in general.

One "We're not really doing contract anymore".

Is it really just a few big agencies who have hoovered everything up these days?