First, understand how a specific technology (new or old) fits into the overall ecology. Often times the flashy new tools and frameworks are really just an abstraction layer for building, or running on top of, an established foundation of traditional technology like SQL, HTML, and JavaScript. The foundation tends to evolve and stick around, while 3rd party solutions tend to have a shorter lifespan, often times getting replaced overnight by newer and flashier solutions. It's only once per generation that there is a major upheaval at the foundational level (ex: DOS -> Windows, On-Prem -> Cloud). So, by learning the foundational stuff you actually are preparing for the future.Will dialects of C, SQL, and HTML still be the primary languages for enterprise application development a decade from now, even after we've move on to the cloud and globally distrubuted databases? Sure, at least I'm betting on it.Will Xamarin and Tableau still be counted among the top ten tools for mobile app and BI development a decade from now? Ummmm... good luck with that.
I'm thinking that's one of the major problems that a lot of people don't actually have and (very sadly) may never have the benefit of doing... learning the foundation/fundamentals, which now seems to be "old stuff" to many.
I can remember decades ago working as a Senior Computer Operator for Data General. Coworker and I were training a couple of Junior Computer Operators. We forced them to use the full commands when doing things on the systems even though we used the "finger savers" to do the same things. We wanted them to understand what was going on behind the scenes with them before we allowed them to use them. There was another Senior Computer Operator on another shift also training a Junior Computer Operator, and he just taught this person the "finger savers" without even bothering to teach what was going on behind the scenes. I had to work with this person for a while and I almost gave them a heart attack when I yelled at them to stop when the nearly relabeled a backup tape that would have caused us to restart the entire backup of the database. This person had actually taken the tape off the drive, looked at the write-enable ring in the back of the tape and remounted the tape for the verification. Had this person removed the write-enable ring I wouldn't have yelled and then asked this person why the command failed.
You need to understand the foundations if you really want to succeed.