But you are kind of proving my point. You just said that you needed to update your skills in order to remain relevant. If you were an aeronatics engineer, mechanical engineer, civil engineer, etc. You will have the basic foundation which in embedded in science and engineering methods that do not change. Have you asked your engineering friends how often they need to "upgrade their skills"?

I'll tell you something. My former mentor studied graphics programming in the 90s and his skills were not obsolete even when he rejoined the 3D industry in 2008. The fundamentals of matrix projection, linear algebra, vectors, etc did not change.

Web development is not a science or engineering discipline. It is more like a design/art field where new technologies come and go and your previous experience has very little carry over. That is why those your friends who did not "update their skills" could not fall back on their previous experience becuase web technologies are so replacable.

A doctor who has not practiced for 10 years is still more valuable than a medical school graduate. Everything the doctor had learnt no matter how long would still be applicable in some shape or form because the science of the human body does not change.

If you stop web development for 2 years, you will be kicked out of the game.