I've elaborated and gotten shouted down enough on the old threads that it's not worth repeating the whole thing. tldr:
1) the beams are not full, so many users are getting unrealistic service since they're not doing traffic shaping in those areas yet.
2) the areas that are full are seeing significantly worse speeds and latencies. see Reddit.
3) Elon said <20 ms pings will be normal. they're averaging 30-40ms in full areas.
4) it's not financially viable without many more users, higher costs, and cheaper launches.