It’s the new things that matter most. All knowledge builds upon past knowledge. You can either build on old knowledge and stay low, or you can build upon the new knowledge and soar to new heights.
Think of it like building pyramids in the desert. You can start building upon a foundation. Without the help of many others, you will never finish the pyramid. Or you can start building upon a pyramid that is already built up high. You will live to see the pyramid gain new heights, or even come to completion.
That is how it is with most pursuits of knowledge, like reading. The books that will bring you to new heights are the recently-written ones that were based on a lot of research. You should read those books and build your knowledge on top of them.
Yes, reading classics can also be helpful, but you run more risk of wasting time. These works have been read countless times over the years. The knowledge has already been learned, distilled, and expanded upon. Why revisit the horse and buggy when you can start with a modern electric car?
The desert field of knowledge looks something like this. One of the highest pyramids is self-driving cars, which is built upon artificial intelligence, which is built upon networking, which is built upon digital computing, which is built upon electricity… all the way down to the concept of basic logic that some things are true and some things are false.
Some of the pyramids in the field may have been abandoned. Bloodletting, self-flagellation, yo-yos, planking, slide rules—these are no longer popular bases to build upon. It doesn’t mean you couldn’t or shouldn’t find innovations building on the knowledge of bloodletting, but it is much more likely that you would be wasting your time in doing so. Some paths of knowledge have been abandoned for very good reasons.
For the most chance of success, it’s better to find something new, exciting, and perhaps a bit scary. Lingering in the past is the easiest way to get left behind. Know the history, but base your work on the new. That is how you innovate.