Like I said, most feats are actually from the lore. The Elder Scroll's lore is incredibly powerful and is one of the most powerful verses.
This is mostly thanks to the Aedra and Daedra who are absurdly powerful, not because of beings like Alduin. Miirak could’ve likely killed Alduin, and comparing Miirak and his master Hermaeus Mora, is like comparing a Tiger to a Volcano.
Alduin has no real feats of power that would put him relative to real Elder Scrolls top tiers. Alduin’s greatest showing of power is simply that he’s extremely hard to kill, and given enough time without being slain and he will eventually eat everything…but immortality/near invulnerability is just scratching the surface of what the Dedric princes are capable of (in their own realms at least).
I dunno if some statements are exaggerated but it is not the case that Alduin consistently gets portrayed as a world eating being, even in-game? I recall this fact at least.
Yes. And if the lore is to be believed, Alduin destroyed the world that predated Tamriel as well. Akatosh also thought Alduin was his greatest creation.
Still not sure as to why that would put him above Ganondorf though. Ganondorf has shown multiversal power like Alduin as I said above. Ganondorf doesn’t destroy worlds, because he wants to conquer them, and literally every time Ganondorf tries to conquer a world or universe, he always succeeds, he is rarely stopped.
Ganondorf has feats as you said, Alduin only has hype.
Doesn't Alduin have some reality/space bending feats?
No. Lol, none whatsoever. Alduin’s greatest feat that he’s actually shown is reviving dragons from the dead. Reviving dragons from the dead is practically something Ganondorf does every time he wipes his ass lol.