It's great to apply "deliberate practice" "10,000 hours" and what else into domains that are strongly stable across time like mathematics, music, some foreign N

It's great to apply "deliberate practice" "10,000 hours" and what else into domains that are strongly stable across time like mathematics, music, some foreign NATURAL language. You get to use the skill in which you invested so much of your time. It sucks to apply even the least of effort into vaporware fashions like programming languages, tools and techniques. You don't even get to complete half of the 10,000 hours of effort to acquire the skill that the whole thing is already antiquated and thrown into the garbage can of history. You wasted a vast amount of time for next to nothing.