For an ISP that uses satellites, ground stations are equivalent to satellite coverage. It doesn't matter how many satellites they have, if there isn't a ground station to connect to you don't have coverage.
Inter-satellite links also don't do anything useful if you don't have enough ground stations. Even if you had a ground station with infinite bandwidth there is no way a single satellite can have the entire network linked through it. It's a really neat thing to have a single voice channel connect through a constellation from somewhere like the southern Indian ocean, but you can't really run 100+ mbps pipes like that.
This is completely different than something like a military communications satellite where both ends of the connection are communicating through the same satellite. The 48 states could be totally in the dark (no power, no comms) and a military communications satellite still functions fine.
The nuance between ground station coverage and satellite coverage is extremely important for understanding spacex's business plan, which is relevant to your comment since you were saying "I don't really understand the business plan of SpaceX with respect tostarlink", with the implication that it doesn't make any sense. The difference between ground station coverage vs satellite coverage is the difference between "we're still building out the infrastructure, but we have the hard bits in place" and "this business model never scales because we need to launch way more satellites just to have basic coverage over the continent". It shouldn't be surprising that they're not done scaling the ground infrastructure, but that's not an impediment to their long term business model, because it's not the expensive bit.
> Even if you had a ground station with infinite bandwidth there is no way a single satellite can have the entire network linked through it.
This is a straw man, no one ever suggested that the entire network would be linked from a single satellite.
Rather the primary purpose of inter-satellite links is that you can expand coverage to areas away from ground stations. You route the traffic to a nearby groundstation (or better, a groundstation close to it's destination) with bandwidth available.
> but you can't really run 100+ mbps pipes like that.
Yes you can, I don't have numbers for starlink's inter-satellite links, but in general that technology is at the ~10gbps / laser link range, each satellite has 4. Light travels through space faster than in fiber, so if routed intelligently this actually lowers ping too.
> This is completely different than something like a military communications satellite where both ends of the connection are communicating through the same satellite.
Ironically, this actually describes how the current system works (as long as you treat the endpoint as a groundstation, and not an IP address somewhere on the internet).
The future system is more robust, even if there is no "other end" to talk to locally, spacex will (with inter-satellite links) be able to route you to an "other end" anywhere around the globe.
Tell us you know nothing about military satcom without telling us you know nothing about military satcom.
Let's see, this system predates even my birth: https://en.wikipedia.org/wiki/Fleet_Satellite_Communications...
It's still in use as recently as 2009, by pirates however. Newer systems include some form of conditional access to prevent anyone with the gear from using them.
It's a bit like saying "a bicycle is different from an automobile, because automobile frames are made from wood", and then pointing to a Morgan to prove the point.
There is nowhere in the lower 48 where starlink has no satellite coverage, I believe there are still areas where they have not built out ground stations though, and since most of the satellites don't have laser links to talk to other satellites (due to issues with their original lasers not fully burning up on re-entry - now fixed) they need to have a ground station under the same satellite as the customer.
They also have limited bandwidth to any one satellite, so they need to limit the density of their customers. Satellites move up and down lattitudes, but at any one time the density of satellites is higher at higher latitudes, so they should be able to serve more customers there.