Compare to fiber. Best ping time is 76 ms, or 38 ms one way. So, our budget margin is 10 ms. Suppose, instead of a direct downlink, packets are dumped to a nearby hub and carried via 1000 km of fiber to the destination, with various routing delays, adding 5 ms, leaving a 5 ms lead, 5000 microseconds.
In finance, we say a microsecond is an eon, a millisecond an eternity. That is because in a microsecond we can do >1k multiplications. 5 ms is time for >5M multiplications, many more than needed to evaluate a position and choose a response.
The only routing choices are which satellite to uplink to, and whether to forward or downlink each packet. Whatever choices are made don't need to be re-evaluated more than per second. Packet queuing delay can be negligible; modern switching equipment will start forwarding a packet while the rest is still arriving; this would happen when forwarding via laser link.
The latency advantage for New York/London/Frankfurt <-> Singapore/Tokyo/Hong Kong would be even more compelling.
There are many things rich people can do, poor cannot. You gotta have money, to make (real) money. Thats the harsh truth and most of us who do not have it, have to struggle hard, to make some wealth and very, very hard and be very lucky and gifted, to get rich by it (without negating all ethics).
London/New York doesn't seem like the distance that there is going to be huge wins for back bone connected entities. But I guess that even if you can land a percentage of packets quicker via starlink, then there is some value in the trading world?