Too cynical. Having been through dozens of these over the last couple years, it genuinely seems like most are just trying to make sure they aren't referring an asshole. One of the many personality filters.

I don't think assholes are common enough to warrant a blanket filtering process. I think this is just a common way to justify closer contact, whether it be phone or video. It really is just sales, and the more personal, the better.

You will be surprised. The absolute worst candidates can stay very long in market and appear everywhere. Someone can look good on paper but a short call can tell you right away that you do not want to deal with them.

Ok, remove any cynicism. I just don't want the phone call, I don't care how 'warm' the other party finds it.

Up-thread they said they explicitly asked for email instead after taking the cold-call. What's the good faith reason for insisting on a warm phone call when it's not wanted?

A 'warmer' (aka 'qualification') means finding out if there is likely a material, beneficial connection between the parties.

In almost 100% of the cases, if a Recruiter is able to get someone a job, it's immensely beneficial to the new employee, far more so than for the recruiter.

While that may be true, the recruiter doesn't get paid if you don't get hired. And even if it is a bad match for you, they still want you to get hired so they get paid.

There is no such thing as a perfect alignment of incentives but there is such a thing as 'no alignment of incentives' and it's better for parties to know that straight up.