Yes, I totally agree, but if you look at scientific studies
While interesting, and different, he's doing some really extreme working of the sample, I guess for contrast.
And certainly I agree that mere stress relieving isn't going to recover that, nor would it be enough for the extreme forming of our cases.
WE only need to recover what WE'VE changed, which is way less.
Truly, we need to be careful with full anneal temperatures, where full annealing is never desired.
While they work (obviously) neither torch nor induction is conservative, due the care needed in timing, so that you don't ruin your brass, including leaching of zinc from the alloy.
Since I haven't had an annealing or annealed case issue while dip annealing since the 70s, it's hard to accept an idea that it does nothing at all.
Pretty sure it's working.
I'm also not sure that Vickers hardness correlates with the hoop tensions we're managing.
Maybe elasticity is more than hardness alone leads to, and so far we don't even have a way to measure what we're really doing.
It's all interesting to me.