I’m not entirely certain what you’re trying to ask so I’ll reword the question to my understanding: “What new tools/libraries/etc would you like someone to create that solves problems developers are facing today?”
I can’t really think of anything that I would like to exist that I’m not already trying to create. My ~/Projects folder is filled with dozens of repos not on GitHub yet which I’m halfway through.
These days, most of my focus is on design systems. Which break down UIs into small components/elements/atoms/symbols (whatever you want to call them) so that they can be composed together to create very complicated designs easily. I’m focusing more on the developer side, but a lot of it is designed so that developers can work more closely with designers and product managers.
There’s a bunch of people at Airbnb who are working in a similar place, but a little bit more from the design side. I hope to meet them in the middle and create the next generation of tooling. I’m doing it so that small companies can innovate at the speed of some of these larger corporations.