Yeah I agree there is too much of that
& with this friend of yours, I'm not even sure how they would report, I know in the past it has been difficult if for example there hasn't been any chat for the last minute.
But I haven't used the report system recently so maybe it wouldn't be difficult?
I always tell clanmates to report no matter what, because having some info sent to Jagex is better than none.
I'm still hoping to learn if my clanmate sent in time or if unbalanced trades at about 1 bil are auto looked at.
I remember something about unbalanced trades in the past but it was ages ago & I don't know the state of play currently.
In the case of your friend there also would have been a massively unbalanced trade somewhere.
I don't think in either case your friend or my clanmate will get anything back, but knowing that the scammers had been perma banned would still be some comfort.