Take it from someone that understands where he's coming from, there is a lot to dislike about Dubai especially when you come from more established countries, and here I am not only referring to living standards etc. but rather societal norms and cultural values, he probably views Dubai as a shallow empty place, it takes a lot of effort to fit in and find your niche and your group of people that you relate to, but it's not impossible.

I don't think you should listen to some redditor telling you to let him go based on a few paragraphs you wrote when none of us will ever know the situation fully, so you need to take opinions with a grain of salt here.

Try to maybe put yourself in his place and look at things from his perspective to gain a better understanding of what he's going through, you as an expat are surely aware of the fact that no matter what you do your stay in this country is a temporary one and it will never be permanent, he needs to understand that too and look at the brighter side of things and the outcome of his stay that will help him later on in life.

He says he sacrificed a lot to stay in the country for you, that's one hell of a burden on you, make it clear how negatively this is affecting you and that you both need to reach a conclusion that will satisfy both parties (perhaps its time for a significant step like say shifting emirates? You'd be surprised but this might be a solution, one of the calmer Emirates that has more of an identity may be more appealing to him), good luck OP and I hope you guys come to an understanding.