I have to respectfully disagree. While this may be true for top recruiters, the SNR is very low in this field - a large majority of recruited are not helpful. Specifically I'm speaking on the hiring side of two companies. In one, we had decided to work with one recruiter who we had a good relationship with and they knew our salary requirements, needs etc. However, on a weekly basis we would get 10-12 unsolicited emails from recruiters who we didn't want to work with introducing candidates.

So from a candidates pov, it's very hard to see if the recruiter even has a relationship with the companies they are passing to. If you have a way to ascertain a good recruiter from a bad (maybe through personal recommendations) then sure go ahead. But I don't think it's useful to use cold call emails.

As another datapoint, I've had several friends go through the job hunt where we each applied to 20+ companies. All of us independently stopped using recruiters when we saw that it was more efficient to work directly with companies.

This is my experience as a junior dev. Ymmv with other roles but I find that the SNR is too low to get any benefit from recruiters.