In the end, it's all of that and more. Geosynchronous is just too far away for good latency, plus the signal is weak and the bandwidth is saturated quickly. So

In the end, it's all of that and more. Geosynchronous is just too far away for good latency, plus the signal is weak and the bandwidth is saturated quickly. So low earth orbit it is, but that meant doing several technology breakthroughs never seen before and at massive consumer scale. First, you need to have massive launch capacity, otherwise satellites wouldn't be in view for most of the world, most of the time. At this ground relative speed, they also stay in view pretty short at that speed, so you need to continuously roam from one satellite to the next every few minutes, hence the need for the cutting edge antenna array. Lastly you need a truckload of satellites. Even the largest fleets are small series productions with specialized, expensive equipment such as radiation hardened processors, flywheels and propulsion to keep in orbit. Mass producing these from commercially available hardware was the third large challenge here. Most companies would go bankrupt just tackling one of these and Starlink pulled them off in parallel. Pretty wicked.