Relax Pappy, I didn't sneer at anyone... it's all f'in opinions isn't it? I thought the comment was funny, and a bit over the top... plenty of good climbers still using leashes.... just no
really good climbers...

I must have been using my leashes wrong the first 3-4 years I started climbing because I definitely adjusted them to support the wrist, which does allow a less
focused grip IMO, at the cost of bloodflow and options I would later find out...
Bloodflow, because it's a leash around your wrist... AND it isn't as easy to shake out whenever...
Options, because switching hands has helped me a lot in the last 6 years of leash-less climbing...
This is the chink in your armor IMO:
"a kind of mental prop so that you relax and don't overgrip"
You just said it... it's all MENTAL... and if you can learn to relax and not overgrip without a leash, then you will climb better.
That's truth in my book, and strongly supported by the best ice climbers in the world...
But meh, climb with leashes/tetheres smoking and pissing all over my frozen winter wonderland just don't solo past me without stopping to chat first...