When the author talks about too many languages and libraries, I personally think he means the proliferation of Unix DSLs (some of which are Posix and some are not) like Make, Awk, Sed, BC, DC, shell-script dialects, Gnuplot (I know it's not Posix but it was widely used once), xargs, Vimscript, ELisp. Each of these has its own quirks and random limitations. Each of these makes Unix unnecessarily complicated and difficult to learn, and they don't even accomplish much that's impressive. I also think they make the editing experience worse, because they prevent the use of IDEs or highly featured REPLs like the ones general-purpose languages have.
I imagine that a lot of this can be replaced with libraries for a general-purpose language like Python. In the case of Awk, BC and DC, Python's standard library does everything these do without their strange quirks. Gnuplot can be replaced with umpteen plotting libraries like Matplotlib. Shell-scripting can be done in a Python dialect like Xonsh. I don't know of a Python alternative to Make, but Make is a fairly perverse and ad-hoc language that looks ripe for being replaced by a library.
I don't think a new operating system (however you define that) is necessary. I think you just swap out a lot of the crazy DSLs with one consistent general-purpose language. People will switch over when they want to accomplish things more easily (like me!). This is especially likely if you're not a SWE but you want to do file system automation anyway. The DSL-heavy approach is too Byzantine for such people (like me!). And it's mostly possible today.
I wouldn't even say any of those make UNIX difficult to learn. 99% of people can be users and developers just fine without learning awk or sed or even make, if they don't do low level work.
It can all be incrementally replaced over time, without starting over, just like how systemd and pipewire didn't need to totally start over.
Make will probably need something more than just a library though, because it's gotta stay declarative. But the fact that make exists at all is kind of an issue. I think build and package management should be done in the language itself like non-C languages do.
The other use of make is almost as a pseudo UI, just a standard place to put a list of actions you can do.
Something like Ansible could replace that, in theory, or we could have some new "project control center" file with menus and inputs and settings.
I imagine that a lot of this can be replaced with libraries for a general-purpose language like Python. In the case of Awk, BC and DC, Python's standard library does everything these do without their strange quirks. Gnuplot can be replaced with umpteen plotting libraries like Matplotlib. Shell-scripting can be done in a Python dialect like Xonsh. I don't know of a Python alternative to Make, but Make is a fairly perverse and ad-hoc language that looks ripe for being replaced by a library.
I don't think a new operating system (however you define that) is necessary. I think you just swap out a lot of the crazy DSLs with one consistent general-purpose language. People will switch over when they want to accomplish things more easily (like me!). This is especially likely if you're not a SWE but you want to do file system automation anyway. The DSL-heavy approach is too Byzantine for such people (like me!). And it's mostly possible today.