Seems odd to argue Piccolo’s city busting feat was only that potent when we know DB characters constantly fire off attacks way more potent than the actual destruction.
King Piccolo is right in the middle of two characters, Roshi and End of DB / Beginning of Z Piccolo Jr. , stronger than the former but weaker than the latter, who have both demonstrated Moon destroying feats
The problem with that is that we have to really move heaven and earth in sheer speculation that DK Piccolo in particular can hit that hard and the issue is that outside of the Roshi Moon Busting, DB never reaches that level of scale ever again.
It's not even referenced in any way either. Remember, we go by Feats > Statements and that what really screws him up.