[cmacleod4]

> Unfortunately high-quality bundling into executables just isn’t a focus of Python (nor of any other high-level language).

You seem to be ignoring Tcl, which solved this problem about 20 years ago with Starkits (https://wiki.tcl-lang.org/page/Starkit) and Starpacks (https://wiki.tcl-lang.org/page/Starpack).