If you're in an area with overhead cables, you can see line extenders (Linex, as the techs call them) hanging from the cable. These are large cast aluminum boxes, with multiple cables connected to them. In those boxes are amplifiers, one for each direction, filters to isolate the directions and splitters. The downstream traffic passes through the high pass filter and upstream through the low pass. Unless they've changed all those filters, the low pass cuts off below 54 MHz. There is no way you're going to get 1 Gb upstream from multiple customers as long as those filters are there. There are also issues with the method used to handle contention that further reduce available bandwidth. And yes, I know about FTTN, as I have worked on this system and others. There are many customers connected to each node, which where the fibre terminates So, have a chat with Shannon and Nyquist to see how you can get all that bandwidth, while also supporting TV, phone, alarms and more.
As an experiment, try monitoring the Ethernet connection from a cable modem in bridge mode. Take a look at all the ARPs to get some idea as to how many users there are on your segment. Since you're running pfSense, you can use the built in Packet Capture to do that.
I haven't lost my mind. It's around here...somewhere...