My personal answer to the titular question is something like "there's only so much you can do with our predominant programming paradigm (i.e. plain-text)". Programming languages specifically can only make incremental improvements and/or tradeoffs in that medium.

Tools like IDEs, debuggers, visualizers, etc are more interesting, but I think their effectiveness is also limited (and creativity constrained) by having to work in a plain-text world.

Moving beyond plain-text is mostly a social dynamics/network effects problem, and I wouldn't be surprised if the intersection between people who are good at figuring out that distribution × people are who are deeply interested in how programming happens is actually quite small.