There really is nothing new under the sun. Below the furiously churning surface of the programming world are calm waters barely disturbed in the past 20+ years. And it's not all that far below, either. I've come to resist learning new techs not because it is hard for me at my age, but because it is too easy, and it is easy to get sucked into spending all my time learning the latest churny surface gloss on old ideas without ever exploiting a particular tech to do something useful because I'm moving on to the next churny surface gloss on the same ideas. Gotta actually build something at some point.
This is what I saw with good Java developers 20y ago, E.g. controlling side effects and trying to distinguish IO and pure methods, in Java, 20y ago.