‘For you bear with the foolish gladly, being wise yourselves. For you bear with a man, if he brings you into bondage, if he devours you, if he takes you captive, if he exalts himself, if he smites you on the face.'
It has become necessary because, in their supposed wisdom, it appears that they listen to fools. Let them then bear with him as he speaks like a fool. They think that they are ‘wise', but he speaks of their ‘wisdom' sarcastically because they are clearly not behaving wisely at all. They put up with those who enslave them, who force them to do what they want; with those who devour their possessions by living lavishly off them; with those who ‘take them' (make them captives to their false teaching or even possibly sexually misuse their daughters under the pretence of religion); with those who exalt themselves and treat them roughly so as to demonstrate that they are in charge. And the mesmerised Corinthians are putting up with it because of the great claims these people are making.
Note the contrast with Paul. Instead of bringing them into bondage he betrothed them to Christ (2 Corinthians 11:2). Instead of devouring their possessions he refused in any way to be a charge on them (2 Corinthians 11:9). Instead of making them captive to his own teaching he brought them the truth (2 Corinthians 11:10). Instead of lording it over them he has been meek and gentle among them (2 Corinthians 10:1) and loved them (2 Corinthians 11:11). Can they not see the difference?