You absolutely do not want to scale the page to the same physical size on different screens because you also need to take into account distance between screen a

You absolutely do not want to scale the page to the same physical size on different screens because you also need to take into account distance between screen and your eyes. Text on phones can be smaller physically than text on a desktop monitor because you hold your phone closer. As an even more extreme example, think of browsing the web on a TV screen while sitting on the couch and how small the text would be if it is physically the same as it is on your phone.