And to top it off, you have Whitebeard calling Garp “just an old man now,” which seals the whole idea.
You realise the old guys always belittle themselves before they pull out some crazy shit right after?
You have Whitebeard admitting he cannot always stay the strongest - I mean, he was terminally ill, so it makes sense - but then split the seas, creates island sized, devouring tsunamiquakes and his quakes are being viberate to nearby islands.
Only someone completely clueless would believe these guys keep the same power in their old age as they had in their primes — it just doesn’t make any sense.
I already explained it above.
The SBS gives the true answer to how strong the old legends are. Do you think Oda was just purposely lying like that to troll for a bit? Nope, it was his message "to not underestimate them only because they are old."
The own author of this manga purposely drew old guys to be near their prime. It is what it is.
Furthermore, yes, Garp's power is declining lately, by how much? Their older versions can still be comparable to their prime even if their strength is just 80% or 90% of their prime. As I said, Old Garp performed similar feats like GV Garp or do you see a huge difference?