I mean, key changes may not be popular right now, but things have a way of coming back around. Sooner or later, someone is going to make a really good song with a key change and then it's going to be back in rotation.
And maybe it just winds up with a dedicated niche audience. Never fully mainstream, but never out of the current culture either. It's hard to predict what people will like in the future. The best we can do is just do things we like.