In any given place there are 3-4 Starlink satellites visible at a time. The bandwidth on each is somewhere in the 20 Gbps range.

So if you have 200 people using one satellite that’s no problem. 800 people using that whole cluster of visible satellites is also no problem. With 8000 simultaneous users you’re all down to 10 Mbps which is starting to get a bit limiting.

Each satellite covers an area about 15 miles across. About 100 square miles.

So… that works out to… something like 100 simultaneous users per square mile max.

That’s all back of the napkin math obviously… 1000 users packed into a small city surrounded by corn fields would be fine. 1000 users around every subway stop in NYC wouldn’t work even if the density is the same.