It makes more sense for a designer to focus on a more adaptive web environment rather than the device breakpoints in order to create a more consistent and cohesive feel to the site. Focusing on the content first makes it far easier to cross over from desktop, mobile and tablets with far less issues with feeling bogged down or even stuck because of the breakpoints. The content is the reason that a user comes to a site in the first place so making a site about the content will allow the user to get what they need across all platforms.
One change I can foresee in the future of web design is more content driven in design in order to allow content to cross over to all platforms that currently exist and the ones that have yet to be released in the future. I also can see how we are moving more towards Scalable Web Design (SWD) by switching from raster to vector based graphics due to the fact that users are using different sizes of devices while not suffering the quality of the graphics. Moving more toward vector based graphics will also save a lot of time and resources as the graphics will not have to be recreated for each screen size. I can also see how vector typography will be more prominent in a content based, simplified future design in order to add character to sites.