What criteria are you using to define 'best'? I'd have thought "can't be replaced with a simple regex" would be a reasonable heuristic, but if you're right then that can't be it...

You're right, scrub 'best'. In their particular area of recruitment, the largest and arguably best known in london. (No names if you don't mind).

I only worked with local recruitment companies back i the day. I’ve met plenty of recruiters in their office an for lunch.

This was pre-remote work. Even now, I wouldn’t just random work with recruitment companies. I work with people. I would reach out to a recruiter on LinkedIn and start a conversation.

Honestly though, at this point in my career, I doubt that I would ever go through a third party recruiter again just because I do have a network.