Again I’m not disrespecting Dragon, saying he’ll lose to Imu before Luffy beats him isn’t disrespectful.
Dragon is important but at the end of the day just like his dad he’s not the right one. Luffy will succeed where his Dad and Grandfather failed, showing that he was the one who took the true path of freedom. He’s also the MC ffs, this is like expecting Minato to beat Madara lmao
Minato is dead, he already passed his will to his son a long time ago
Destroying the WG corrupted core has been Dragon's mission for decades
When asked who were his candidates for main characters besides Luffy; he answered Dragon and Garp.
So in a way, with all the build up he has done for Dragon and establishing his reserved leadership along with his mysterious identity and abilities, it will eventually reach the point where he can unleash this beast of a character.
I don't think Oda has it in him to diminish the greatness of Dragon's character even for Goofy, especially when Imu is likely to be a godly entity if she's gonna be an actual combatant
Remember, Naruto defeated Kaguya with Sasuke. Dragon has more claim to fight Imu than Luffy does.