The bandwidth is so slow for this direct-to-cell service that it won't replace mobile providers. The bandwidth for a whole cell is 20Mbps, except that is shared with the thousands of people in the cell. I have been thinking of it as 2G phone service. You get text, voice, and little bit of data.

It probably isn't physically possible to do phone with Starlink high speed service. The dedicated antenna would be better than existing 4G/5G but small size would be a problem. Also, the Starlink antennas depend on having good view of the size.

Finally, the market is tiny of people wandering in the wilderness who want high-speed data. Starlink competes with itself since its service can be used for remote camps; there are rumors of a smaller antenna. Starlink even makes it easier to setup wilderness cell towers and microcells at house.