So, I wrote this little thing both since I needed to write it down for my coworkers anyhow - this is how we do things, showing respect for candidates by keeping reciprocity, incrementalism, and relevance in view - but also in the hopes that it's one more brick in a wall of "you're worthy of respect" for candidates.
The post itself wasn't about our actual process, though I did use examples from it; I hope to write about the actual process later. But I will note that my experience of phone screens is apparently very different from yours: I've experience them as a chance to pre-grill and filter candidates, and ours is 100% not that. I ask zero questions, but instead just talk about what we do and answer any and all questions candidates have. You're right that doing an intro call with each candidate isn't scaling, but we're not replacing me with HR, but instead have a live weekly intro call that candidates can join where I talk about the company and they can ask questions via text and I answer them on the spot.
And for what it's worth: "the current market dynamics" in tech hiring SUCK. So long as I have any say, we'll be playing moneyball by ignoring them and instead just continuing to iterate based on what actually works.