Is it considered oppression for a husband to give his wife the choice between remaining married to him without intercourse or divorce, after he developed a dislike for her due to her shortcomings and a lack of harmony between them, and the wife chooses the first option?

There is no harm in a wife waiving some of her rights to her husband, with her consent and free choice. For instance, she may waive her night for his other wife, just as Sawdah (may Allah be pleased with her) did for Aisha (may Allah be pleased with her). The marriage contract remains valid. It is advisable to attempt to reconcile with the wife before rushing into such matters, due to Allah’s saying: "And live with them honorably. If you dislike them, it may be that you dislike a thing and Allah brings through it much good."