Latency can definitely improve from where we are at. The speed of light is different through different materials, that's why some people are using hollow fiber

Latency can definitely improve from where we are at. The speed of light is different through different materials, that's why some people are using hollow fiber optic cables to have lower latency connections. Laying a more direct line would also improve latency, my connections to Seattle backtrack about a hundred miles east before heading out west again according to traces. Faster routing hardware would shave off a few milliseconds. Economic factors hold back latency improvements for the majority of internet users, not hard physical limits.