How many freelancers have an agent/manager?

I’ve been freelancing for about a decade now, pitching journalistic pieces and essays, and starting to wonder if I might want to get an agent or manager to help solicit or manage commissions. Curious if anyone has experience with this, could speak to the benefits, or knows the prevalence of prominent / prolific freelance writers who do have this. I just have no clue if it’s normal or common. (I worked in a literary agency for a while so I know a bit about the process of getting agented for book writing, but less so for journalism.)