But that is the job. The job of developing on the web is developing for a platform where you do not know the size or format of the display or what the inputs ar

But that is the job. The job of developing on the web is developing for a platform where you do not know the size or format of the display or what the inputs are in advance. The job of a UX designer on the web is to consider this kind of stuff and to build a design that's very reactive to evolving displays within the demographics and market segments that the client wants to support. If that's not happening, if the CSS people are just getting handed static designs and being told to figure it out -- the problem is not CSS or the developers, it's that the designers building those designs are not good at their jobs. And there are ways to make this easier: notably UX designers involving the CSS department in the design phase, and/or making a point to always lay out the contents of the page without styling in a hierarchical way before making decisions about how to present that content. But a lot of programming is hard. It's hard for me to write maintainable Javascript that doesn't fall apart if a project goes over 100,000 lines of code. It's hard to document methods. It's hard for me to write code that does complicated things that can work on low-end machines. These are skills that programmers get better at over time with practice. Responsive design is the same; it's just another skill to learn. Imagine trying to shoot a movie and having the cinematographer tell you that it's hard to frame everyone in the shot since they don't know exactly where the viewer will be looking, or the sound mixer telling you it's hard to balance dialog and sound effects so everyone is audible without it being noticeable that they're muting background audio. Or a recorder telling you that it's hard to master a pop song given that everyone has different speakers and sound profiles on their headphones. Imagine you're building a car and the designer tells you that it's hard to make sure the controls can be reached by people who are different heights and weights. On one hand, yes it is; all of that stuff is very hard. On the other hand, yes, that is also the reason web UX designers and developers get paid money; because the job is hard and requires training and expertise, and designing a website interface requires more thought and intentionality and planning than is required to make a PDF.