1 mile away, both of us have AT&T fiber, we're seeing 10-15ms response times (packet size ~1400).
100 miles away, both on AT&T fiber clocked in around 18-20ms
1 mile away, one on AT&T fiber the other on Comcast gigabit had response times around 24ms
100 miles away, one on AT&T fiber the other on Comcast gigabit had response times around 35ms
i'm hard pressed to believe you will find an american ISP that prioritizes low latency. verizon 5g home actually did some magic with their non-standard hardware where i was seeing 9ms to my in-town datacenter and 16ms to my out-of-state datacenter. when they replaced the hardware with the standards-compliant generation of hardware my latency increased to 30ms in-town (they also changed towers so that could be part of the problem, plus congestion during prime time)
i just moved where i am 6 blocks away from my friend who i did the 1 mile test with. i will retest this afternoon and update this comment