Rod of Ages honestly is a rather boring item choice
All it does is function as a stat stick, and even though it might give plenty of stats, that doesn't come across as exciting or dynamic. One could say the same for Rabadon, but at least that one gives a crapton of AP, so it's justified.
I also don't see many people even go for Rod of Ages, instead getting either
or
because of their active effects. It's kinda sad, and any attempts to make Rod of Ages give you more stats just get it nerfed into the ground again.
I'd like it if Rod of Ages could get some kind of active effect to make it less boring, or could give ridiculous stats after, say, 20 minutes in your possession.