Why wasn't it revealed as to why Q was dying? Strange how it was part of their mythos that Qs were omnipotent and ageless and invulnerable to any attack and yet this one, the worst of their kind was suddenly about to cease existing and had been aging too although I think that was explained as he wanting to be the same as Picard who had aged (even though he was no longer human himself) if John DeLancie had of been ill or sadly dying himself I could have understood the theme but thankfully as he isn't I find it a bizarre concept!
JB
Q aren't invulnerable, during the Q-"Civil War", they made weapons that looked like US "Civil War" weapons that could hurt another Q.
So the myth of Invulnerability is just that, it's a "Myth".
Him wanting to look closer in approximate human physical age (For the sake of the VFX staff, ergo using normal John DeLancie as he currently is) is because he wants to.
Here's the ENTIRE ST Timeline, or at least covering a portion of them.
The Female Q that John DeLancie's Q mated with was born ~5 000 000 000 years ago.
And given that the Q can arbitrarily travel through time at a whim.
I wouldn't be surprised if their life-span is truly vast, some ridiculously large # that we have a hard time grasping.
Like 2^64 ~= 18 446 744 073 709 551 616 ~= 18 Qunitillion, 446 Quadrillion, 744 Trillion, 73 Billion, 709 Million, 551 Thousand, and 616 years old.
If that was their natural life-span, it would be a "RIDICULOUSLY" long life-span.
