I have 1Gbit Ethernet yet I have a 1TB data cap. A witness node uses about 250-300GB of traffic/month from my observations, an API node far more than that.
I also live in an area where we get snow and occasional bad weather that can knock out the power for 1 minute to as long as 4 days.
More and more ISP are implementing data caps, Comcast just announced they will be enforcing data caps for everyone, previously it was only certain states.
While 99% of the time, my connection is fast and reliable, I avoid hosting anything off it due to these issues.
One of the problems issues I have been noticing lately is not all API nodes are running the latest version or correctly functioning, but to HAProxy they would return a heathy status and would continue to serve traffic.