The latency promised is obviously for the satellite segment, any DIA end user with a clue knows that terrestrial fiber latency to and from various places will vary based on where you are and how your local ISP is linked to nearby ix points and peers.
I can tell you what the latency is on fiber from the Redmond or North bend Earth stations to downtown seattle, and it's minuscule. Same as if a person was a customer on a docsis3 or GPON network in Redmond.
Ahhhh, so when Elon musk himself says pings will be < 20ms, he's talking about just the satellite segment, right? because obviously everyone pings just the satellite segment.
It does matter. When you make claims that a small group of people say is not possible and are quickly shouted down, only later to be completely ignored, it matters. It's the same reason FSD coming "next year" for 5 years matters, or having 20k satellites in service by 2021 matters. You say these things, people believe you and prop you up like a god, but when you fall well short it's "not a big deal".
If you recall there was non-stop chatter about how HFT would be using Starlink because the latency was so low, or that it would replace fiber because the latency would be lower. It was all fake. The latency will be 30-40ms nominally for most users. That's great (it's just okay for LEO) for satellite, but let's not pretend it's anywhere near what the goal was.
I can tell you what the latency is on fiber from the Redmond or North bend Earth stations to downtown seattle, and it's minuscule. Same as if a person was a customer on a docsis3 or GPON network in Redmond.