Mark Lowe, co-founder of London-based Third City, said: "Ultimately there are too many PR agencies.
"I sit in London with a proliferation of corporate boutique agencies; there are so many of them. I think that is a market issue. The market will probably correct it at some point."
Lowe suggested the solution is "fewer PR agencies that were better".
Speaking on the same panel, Babel CEO Ian Hood said the PR industry "shoots itself in the foot" regarding how it looks after its workforce.
"My view on that is agency principles cause that problem," Hood said. "They have people working till 9 o'clock at night, they allow some clients to be a real pain the arse rather than dumping them, which is probably what they should do. They work for companies that are questionable from an ethical perspective.
"Those are all problems that agency principles have to address themselves. It's very easy to run an agency and take on every brief that comes to you; don't do it."
The panel at the seminar - entitled 2020: The Year Of... - also discussed whether we have reached 'peak purpose'.
"I guess the feeling is we've reached peak fake purpose," said Will Cook, executive director, strategic and innovation at Golin, which hosted the seminar.
"What we need to get to, and what we need to understand, is that purpose needs to be more than just a comms campaign."
He pointed to the fact many firms will need to prove their commitment to environmental pledges after setting sustainability goals for this year.
"How many corporate comms people are now freaking out because actually they had a great campaign for 2020 vision but who followed through with it?"
Do you agree there are too many PR agencies? Share your thoughts via firstname.lastname@example.org or tweet us via @prweekuknews.