[vel0city]

> cable modems really have not suffered congestion beyond the ordinary

I've lived in and had friends live in apartments with absolutely terrible noisy neighbor problems on coax networks. Too much junk plugged in making all kinds of noise on the same run making internet services close to useless. DSL infrastructure lost out to cable at the start in that area so it got practically no upgrades since it was first implemented. While far more reliable it was ancient speeds at even higher prices.

It seems like it largely took 5G home internet actually being a thing in those areas for the cable companies to start fixing those buildings and rooting out the problems.

Cable modem congestion and line quality issues definitely vary greatly on the operator and the actual location installed at. A cheap old apartment building filled with poor residents is likely to have abysmal line quality. A well-off neighborhood of single family homes probably has no problems with line quality at all.

[wat10000]

It's a lot easier to upgrade the capacity at a central office than it is to upgrade an entire neighborhood. Plenty of cable infrastructure was built out when it was just a broadcast (multicast?) medium and the only concern was making sure signal strength was adequate at all receivers. If you repurpose that wiring for emulated point-to-point transmission, there may not be a whole lot for each individual.

Random example, my house has fiber and cable available. The internet plans are similar, except fiber offers 30x higher upload speeds, which is a direct consequence of better topology.