Frameworks, languages, computers, come and go, but the human body doesn't change and the knowledge I have in design, I carry every day and have barely changed over the years. Sure there are new patterns now... "hamburger buttons" and swiping, but the logic remains the same. Human's don't change quickly. They discover things the same way.
Learn about visual hierarchy, visual rhythm, visual grouping, visual contrast, visual symmetry; the golden rule; the theory of colours etc. Think "subject" first, like in photography. Design for first glance & last glance.
Go beyond "do these align".
Think in the eyes of your user as if it's their first visit, there is no content yet, etc; as well as if it's their 1000th visit; cater for both cases; first and power users.
Understand the gestalt, understand the psychology behind design... Why does bright-red jumps at you, at a visceral level?
Feeling that something feels right is great, but understanding deeply why it feels right is a superpower.
Understand the human brain, its discovery process (how do babies discover the world), "why do westerners look top left first"? And you might innovate in design, instead of designing to not offend anyone; or worst, copying dribbble and other sources because "they spent the money".
Trust me if you can learn React or Kubernetes, you surely can learn the gestalt and understand "the design of everyday things"! That knowledge won't expire on you, you'll start seeing it everywhere and you'll carry it for the rest of your life.