Jesus is comparing his generation to children playing in the public square and complaining to their friends Saying
“‘We played wedding songs, and you didn’t dance, so we played funeral songs, and you didn’t mourn.’
For John didn’t spend his time eating and drinking, and you say, ‘He’s possessed by a demon.’ The Son of Man, on the other hand, feasts and drinks, and you say, ‘He’s a glutton and a drunkard, and a friend of tax collectors and other sinners!’ But wisdom is shown to be right by its results”
Jesus is saying here that no matter what anyone including the son of God does non believers will complain back then they was complaining saying because Jesus was a glutton and drunk just because he ate and drank and because he befriended sinners and tax collectors but at the same time they would complain on John the Baptist because he didn’t go to feast and drink and they called him possessed . So no matter who did what the non believers would complain and judge any body who was a prophet or follower of Christ because it wasn’t to their liking or because they would not “play” the part as a prophet or messiah should to their point of view but also everyone has a different perspective so no matter what someone wouldn’t be pleased would complain because no matter what they found Fault in Jesus
This is a lot like today when something goes wrong people complain and say we’ll why did God make this happen or God should have done this instead of this or guyshey even complain and fight because they believe God is black, or a woman, or something else so no matter what back then and even now everyone has a different perspective and will always complain because it’s not how they imagine or want God to be.