The maturation of web design, simplification of engineering, and sophistication of users’ tastes has created an environment where designers are strongly incentivized to not just learn the basics of HTML and CSS but become full-fledged front-end engineers. It’s not hard to go from there to coding entire apps on your own and moving into the back-end.
This is a nice overarching view of our industry’s landscape. Lots of trends are leading towards people doing more of everything and less of one thing. That seems to be a result of so much of the stack relying so heavily on multiple parts that you need to take time to research each bit. That leads to more intrigue and more time spent researching additional pieces you weren’t familiar with. There was a time when being a Jack of all trades meant you were a master of none. Perhaps that time is long gone around here.