Re 1st point: and kids are often heavy bandwidth users in evening. Network bandwidth is mostly about supporting peak usage, a pipe with capacity per second and not a fixed volume per day. Plans often regulate by volume cap, but high capacity networks regulate by bits per second peak usage.
Re second point: you are misquoting, and making a point that is obvious. The next sentence is "The smart move would be to tell Netflix to downgrade more aggressively" to help your canonical zoom conference (which is a super poor example - apparently Zoom failure is due to Zoom and not network capacity).
While the widespread zoom problems are due to issues with zoom, highly latency sensitive applications like VC will be degraded before a Netflix client even realises anything is happening on a network reaching saturation. It's very hard for the client to be a good citizen in this situation. Network-level QoS would help, but is a massive moral hazard (and generally illegal in the EU, anyway).
Re second point: you are misquoting, and making a point that is obvious. The next sentence is "The smart move would be to tell Netflix to downgrade more aggressively" to help your canonical zoom conference (which is a super poor example - apparently Zoom failure is due to Zoom and not network capacity).