The new JS framework, the new app development framework, that new CSS framework, there are so many things to learn when you write software for a living. Its easy to spend most of your time learning new tools.
With so much focus around new software tools, I wish there was also more focus around optimising the end user experience. Does adding the new JS framework increase the page load time? Do you need 4 different fonts on that single page? Could those 10 images be pre optimised before being displayed to the user?
These questions are almost always an after thought. I wish this wasn’t the case.