When I look at the list of "technologies" the author invested in learning ... no surprise it's all technical debt or deprecated: all the things he lists are com

When I look at the list of "technologies" the author invested in learning ... no surprise it's all technical debt or deprecated: all the things he lists are completely superficial and have obvious short-term, "I can make money now with this stuff" flavor to them. Had the author invested in learning stuff like math, physics, cryptography, advanced data structures and algorithms, functional programming theory, 3d programming, compiler theory, database theory, etc... None of it would be obsolete today, and all of it would be almost immediately applicable in any language that happens to be the flavor of the day at a given point in time. Let that be a lesson to all of the folks who become extremely proficient in the latest react-like fad javascript framework: in 10 years time, all your knowledge will be useful for one thing: maintaining and patching old crumbling code piles that no one wants to touch. Do yourself a favor instead and go learn timeless things that will still be completely relevant 20 years from now. Then spend a minimal amount of time learning how to apply it in whatever language/framework of the day is fashionable at your job.