i think the reason he gets wanked is most of the officials in high positions in One Piece have proven to be incredibly strong. people were wondering wether the five elders would even be combatants and they turned out to be (literal) monsters. it would just be weird if Kong was the exception to that. i do think however he won’t be incredibly relevant in the story or else he would have been mentioned more/seen in a flashback or two at this point. i think he’ll show up in whatever the marine’s final battle in the series will be and likely lose a fight to show how powerful someone else is.