Grok this

Tim Berners-Lee, founder of the world wide web, recently published New Top Level Domains Considered Harmful in which he articulates succinctly the fundamental philosophy of the World Wide Web. I'll quote a pice of it in full to save you the trouble of fining it. I tried to find particularly salient points to emphasize, but I couldn't. It is all particularly salient.

The Web must operate independently of the hardware, software or network used to access it, of the perceived quality or appropriateness of the information on it, and of the culture, and language, and physical capabilities of those who access it [WTW]. Hardware and network independence in particular have been crucial to the growth of the Web. In the past, network independence has been assured largely by the Internet architecture. The Internet connects all devices without regard to the type or size or band of device, nor with regard to the wireless or wired or optical infrastructure used. This is its great strength. From its inception, the Web built upon this architecture and introduced device independence at the user interface level. By separating the information content from its presentation (as is possible by mixing HTML with CSS, XML with XSL and CSS, etc.) the Web allows the same information to be viewed from computers with all sorts of screen sizes, color depths, and so on. Many of the original Web terminals were character-oriented, and now visually impaired users use text-oriented interfaces to the same information.

For a time, many Web site designers did not see the necessity for such device independence, and indicated that their site was "best viewed using screen set to 800x600". Those Web sites now look terrible on a phone or, for that matter, on a much larger screen. By contrast, many Web sites which use style sheets appropriately can look very good on a very wide range of screen sizes.

Designing and developing for the web requires many skills, but until someone has really really internalized the above philosophy, you may be a web developer, but you are not a world wide web developer.