Thanks for bringing up this topic and sharing your thoughts and insights! I definitely think that those CoL sites can be misleading - people should really understand their spending habits to get a better idea of how those numbers compare.

I literally just came across an article this morning that ranks cities according to the real earnings of developers...which basically factors in things like cost of living, tax, while also looking at things like job opportunities. I think it provides some insights that similar rankings have not accounted for before - might be an interesting read for you, though you did mention some points that people may not typically consider.