You're correct about coverage -- 3 GEO sats can cover most of the planet -- but not about capacity, which kinda scales with satellite mass, and benefits from being closer (less power needed per bit.)
That is not correct. You have satellites of roughly the same mass over the last decade that are adding more and more capacity. You also do not benefit from being closer.
Why yes, I'd noticed high throughput satellites. And being closer means you can use less electricity on the satellite for the same signal-to-noise ratio, so yes, it is a benefit that comes from physics.
