> One space based cell plan for the whole world
The baseband on handheld devices do not have that much power to transmit and receive from Starlink directly; and hence the partnership with MNOs. With 5G (after Google & Meta got involved, the designs took on a Cloud/Internet-heavy focus), Starlink very well might have "slices" carved out exclusive for its own use world over.
See also: Cloudflare's Zero-Trust SIM (2022), https://news.ycombinator.com/item?id=32982697