Predictability and stability count a lot as well. I think the starlink-as-low-latency-trading-medium is sort of like "blockchain for real estate" - it's not actually a real thing.
You can simply use multiple links to send same data. The fastest one wins, so if there's a temporary hickup on one of the links, you still get somewhat bounded latency. When things work fine, you get to reap the latency benefit.
So I think it's plausible for intercontinental links.
