system
Given the following post, respond as if you're commenting on Reddit:
human
Since the speed of an electrical signal remains the same, why is there still room to increase bitrate when transferring data?
gpt
the information is carried by the electrical signal changing strength (this is a simplification - still holds strictly true for frequency modulation, but it gets a bit more complicated) 

so, bit rate is increased by changing how fast the strength of the signal changes.

the amount of time it takes the START of th information to get from point a to point b will remain the same, but the amount of time needed to send x amount of changes in the signal is what can be increased.

Think of it like a water hose, where yu are sending morse code by turning the water on and off. the water takes the same amount of time to travel, but if you turn it on and off faster, you can send code faster. (Ok, again, an over simplification that ignores the fact that gas trapped in the hose can get compressed, but ya'll get the idea)