Nevertheless, I am also quite convinced that an enormous amount of complexity is software is (in many cases) simply due to poor practices or a fundamental lack of understanding (or proper application) of basic things like proper composition/decomposition/factoring of code, choosing more complex paradigms due to bias or hype, etc. If that could somehow be fixed (which may only be possible on a small scale, e.g. individually or on small team), I think that would do more for software than any new language could -- unless it truly was something fundamentally different than a traditional language

Yeah. I think our systems don't afford good decomposition. Consider how much functionality is reimplemented over and over. Not because we choose to, but because we have to.