Sure, but advocates are talking about multiples of increased productivity, and how can that be defended if it doesn't scale to a project of some size and complexity? I don't care if I get a Nx increase on a small script or the beginning of a project. That's never been the pain point in development for me.

If someone said that, over a significant amount of time and effort, these tools saved them 5% or maybe even 10% then I would say that seems reasonable. But those aren't the kinds of numbers advocates are claiming. And even then, I'd argue that 5-10% comes with a cost in other areas.

And again, not to belabor the point, but where are the in-depth workflows published for senior engineers to get these productivity increases? Not short YouTube videos, but long form books and playlists and tutorials that we can use to replicate and verify the results?

Don't you think that's a little suspect that we haven't been flooded with them like we are with every other new technology?