Simple answer: Writing a responsive site is much faster and easier to maintain than creating two versions of the same site.  And it wouldn&#x27;t it be just two, you also have to support tablets, various desktop sizes, and various mobile sizes.  Custom versions for each one isn&#x27;t feasible.<p>Also, if you care about page and weight and optimization, your site will be light everywhere, and the criticism of shoehorning a big bloated desktop site into a phone won&#x27;t apply. This is not that difficult to achieve.