[jmyeet]

I disagree with this. You're touching on two separate issues.

The first is that many US broadband connections are on traditional cable systems (or HFC). And these are a shard bus design, meaning you and your neighbours are competing for bandwidth. This is a common cause of degredated connections.

Compare this to fiber The fiber connection isn't shared at all... until you reach some junction, exchange or node. There are various flavors of fiber (eg FTTH/FTTP, FTTN, FTTC).

This brings us to the second issue: bandwidth beyond the last mile is also oversubscribed and it makes zero sense to do it otherwise. Residential customers in particular just don't use that much bandwidth and they don't use it consistently. I mean a gigabit connection is enough for 30+ 4K streams at once at pretty much max quality. But being able to burst bandwidth for fast downloads is really nice.