- data throughput orders of magnitude higher,
- the ability to use smaller and more portable antennas (e.g. ~100 Mbps with something the size of a textbook, currently ~2 Mbps and soon ~10s Mbps with your normal mobile phone),
- order of magnitude lower latency compared to GSO satellites.
Other constellations like Iridium dedicate large portions to use by government(s?), too, but simply do not have the throughput or total bandwidth that Starlink does. Your speeds there, on the expensive business plans that offer it, are measured in the low Kbps.
In Guam it means 10Gbps without Fiber.