I'd say they already know the paradigms & architectures so they don't throw themselves at the latest fad as easily and above all seem to value family more highly and lets be honest. Back in the day you had to learn some pretty amazing tech (assembler and low memory data structures) just to get by.
But yeah, just today there was a comment here on Hacker News saying (I'm paraphrasing): I learnt C then C++ then Java, then enough was enough. Which is just sad, that's like going from oatmeal to porrige.
The flip side of that coin is the drain that comes from...
Learning C, then C++, then Rust, then Java, then Ruby (rails), then Objective-C, then Swift, then JavaScript, then Angular, then React, then Flutter, then ....
Depending on the timeframe in which all that learning happens, there's simply no way you can reach expert level with such a diversified knowledge base.
> there’s simply no way you can reach expert level with such a diversified codebases.
What are you talking about? I’ve checked in production code in 4 languages in a day.
Once you learn your first few languages you should be able to learn the new syntax of a language in a day or two and a good portion of their idioms in the next month (as you know more languages you’ll notice what’s unique about each language and glean idioms from online tutorials and your local codebases).
Being a polyglot is a huge part of many in our industry, especially full stack development. For one project alone I had to work with a backend that was part Java and part Go that hosted customers’ Node backend. I oversaw client SDKs in Objective-C, Java, and C++ and helped prototype the server-side SDK for Go. That’s not fatigue, it’s enjoyable and a skill I can offer my team. Sure I get rusty with a language, but it doesn’t take long to blow off the dust with a skill.