Technical explination on speeds, its demand and they are not supplying the speeds to fill demands put on for peak times causing the slow down of data speeds and its worse when you hit the download limit. maybe a good idea to start reading your contract fine print for 'shaping' aka throttling of data. they all do this so they can line pockets with cash and not spend on upgrades, also depending on where the main street box is you could be the last on the line because thats where they run the copper lines from since its cheaper then upgrading all the lines.
Also alot of the internet and phone lines are still run along with power lines since its easyer then digging and laying pipes to data centers, my brother does road works and brought me some of the converter stuff they use in the cabnets on the poles.
This is the main street cabnet they use.