Would a man be sinful if he divorces his wife due to an obstruction in her vagina, coupled with his aversion to having intercourse with her, and the wife's desire not to be divorced without maintenance?

There is no harm in divorcing one's wife if one dislikes cohabiting with her. However, it is preferable to retain her and try to overcome the aversion, for Allah may place much good in that, as He تعالى said: "And live with them in kindness. For if you dislike them - perhaps you dislike a thing and Allah makes therein much good." And one should consider her righteousness and religiosity, for the Prophet ﷺ said: "A believing man should not hate a believing woman; if he dislikes one of her characteristics, he will be pleased with another," and "attain the religious woman, may your hands be dusted."