Like others have said, we built our pool because we wanted one and solely for our enjoyment in the years we will be in this home, which will be for quite a few or else we wouldn't have done it. Never was ROI or adding monetary value a thought in the process.
That said, if anyone looks at before and after pictures of our backyard and sees the transformation from a basic run-of-the-mill backyard with little landscaping other than grass, limited seating areas and really pretty unusable in the heat of the summer to the gorgeous outdoor oasis we have now with not only the pool with water feature, but nice landscaping surrounding it and 500 SF of decking adding two more sizeable seating areas, I'd be shocked if they still thought it wouldn't add some significant value. Probably won't recoup what we spent, but there is value there for sure not only from a recreational and aesthetic standpoint, but also the standpoint of adding to your overall usable living space, albeit outdoors.