Strong reasons to have a website that suits all screens
The web designer will set on his chair and squinting should browse the page. Inspecting web design this way, you get the same results as any new user. The reason? It is pretty obvious, people do not read, just flick. Following this, can you then find the information easily? ¿click where you want?. If the answer is negative, the web design should be improved. It should make web content more visible and so, increase the font is not only writing and probably reduce the content.
If you want to take further evidence, should make a web design test users. Place a third person in front of web design and give no more than ten seconds to find specific information. If the user performing the test is found, you can conclude that it has developed a good web design in relation to textual content. If he cannot find the information required, re-think your web design.