Companies are still currently not focusing on building web accessible sites. Sure, they are focusing on mobile and desktop experiences, and that’s good. But web accessibility standards are important for making the web accessible to all.
The user experience (UX) is not just how pretty things look. It is all encompassing and it must adapt to those using devices to improve their experiences. Colors must contrast each other well as to not to be straining to the user reading your content. Your site must not have heavy flashing as well. Not just because it is annoying, but especially if you do not provide adequate warnings, flashing lights may cause physical discomfort. Do you want to provide discomfort at the risk of losing repeat visitors?
Web sites either detect the user’s device and redirect to the appropriate version (old style), or readily adapt to the device’s size and screen resolution. This is the new and current style. We call this mobile responsiveness. This method has been improved to include the plethora of device sizes. Early on, it was either phone or desktop. Back then, phones were only 3.5″ and desktops only had 1024×768 or at largest, 1280×1024. Now we have 1920×1080 or even larger desktops. We have phones in excess of 6″ as well as tablets ranging from 7″ to 13″ with resolutions of excess 2000+ pixels.
How do you decide what to develop and optimize for?
Use your web analytics software (you’re using one, right?). Determine which devices people are using. Focus on optimizing for those being used the most and adapt for the in-betweens. Know your user’s operating system because Windows and Mac have subtle differences that can display colors and fonts differently. Be aware of these differences even though you may not care, so that you could know what to optimize should you want to in the future.