Astral are winning mindshare because the tooling is so much better than the previous generations. That’s the action that’s required here - to be the compelling choice, rather than another choice that’s pretty much like the others and differs only a little.
People don't agree that "package tooling fragmentation" is an actual problem, anyway. I'm one of them. The real problem is that a few of the basic tools (mainly, Pip and Setuptools) don't work properly. They have fundamental design flaws and are ridden with technical debt. The underlying implemented standards have also lagged behind, and Uv can't actually fix that.
But once a solid base is established, I don't actually want to have a single tool making all the package management decisions for me. I want Unix-philosophy tools that handle specific individual development tasks, built around a proper, integrated user tool for installing applications and libraries (Pipx would be very close to such a tool, if it exposed its underlying Pip copy more elegantly and if Pip didn't suck). I don't want someone else's "project manager" to decide for me what build backend to use, or even to just bundle one. And I'm perfectly happy using `build` as a build frontend, `twine` as a PyPI uploader etc. Writing `uv upload` or whatever it actually uses, is not an improvement to me.