I guess I don't understand the sales argument for a 'smart monitor'.

For the "smart TV" the argument to the consumer is either 1) to access OTT services if you don't have a device for it already or 2) that the data harvest subsidizes the product.

Neither of these arguments make sense for a straight monitor.

People generally don't buy monitors if they don't have a PC, game console, or some other video source to plug them into. So "it runs Netflix or Zoom standalone" isn't gonna move the needle.

The subsidy argument is also pretty hard to make. It works for TVs because you can advertise "60 inches with malware for the same price as 32 inches without". But monitors have fairly low upper limits on desired size when you're using them at a desk. Many would find a 60" screen overwhelming, but 27" is reasonable. You can buy a new 27" 1080p IPS monitor for $95 today. Can ads and data theft subsidize it down to $80? Maybe. But again, will that make much of a difference for consumers?

This is also only from a consumer perspective. I can imagine IT department having a fit about these products. At the best, it's support tickets when someone accidentally engages with an unexpected feature or plugs their Ethernet cord into the monitor. At worst, it's a fun new source of compliance obligations and patch processes.

The worst-case angle I can see is eventually media entities will see it as a way to close one more loophole. Someone will launch a service that can't be streamed on the host PC, only on blessed smart devices themselves, to eliminate the risk someone plugged the DisplayPort cable into some sort of DRM-stripping device. But that would alienate a hell of a lot of potential customers.