Actually, compilers are a great example of this dynamic - when you work becomes more and more impactful, but more and more removed from actual problems people h

Actually, compilers are a great example of this dynamic - when you work becomes more and more impactful, but more and more removed from actual problems people have. Say, you write a script to solve a specific problem someone has. But that is not very impactful - one person is happy and that's all. So you generalize your program to a whole class of problems. But that's not the end. Next, you write a framework for writing programs similar to the one you've developed on the previous step. And of course, all languages being shit, you'll want to write a compiler for a language to write your framework in. So you end up with a thing that is very impactful but also pretty useless on its own.