Google likely pays for them to do so,
since then they can embed telemetry/spyware into the monitor and collect data about your usage, which they'll sell to advertisement companies and give to law enforcement if requested.
I absolutely hate it already.
Same as I hate that you can't buy non-smart TVs anymore for the same reason...
I used to block telemetry network wide using a PiHole, and the smart TV of one of my room mates made up 2/3th of the network requests after setting it up, before it realized that it's telemetry connection was unavailable.
Strongly recommend to keep these devices completely offline, and instead buy a RPi or something of the likes to flash a privacy respecting Android TV fork onto it, e.g. LineageOS.
However it does frustrate me that the licensing costs of these unwanted spyware products, which I'll refuse to use, are pushed upon the user, with nearly no ability remaining to buy a device that ships without it...
I guess a some people use monitors with laptops as a dock. Nowadays with a single usb c to the monitor can charge the device and recieve video signals. For them the monitor is still usable as something, even if the laptop is not there.
So I see some people might benefit from this, but it doesn't seem like a very useful feature for the masses. Other manufacturers' also had similar monitors, fortunately it's not very common, I remember LG had one last year:
I'll start off by saying this isn't a feature anybody wants.
However
The "nobody asked for this" rhetoric is dumb. Most of human history actual upgrades nobody asked for.
"God this radio is so inefficient it doesn't immerse me fully, if only there was a way I could see what was happening" - nobody
Computers were a fad that nobody asked for
Debit cards, no one asked for.
There are other things that you use in your daily life that nobody asked for.
In general if we waited till the majority of people asked for things we'd be in the stone age because the vast majority of people can't think past the next couple of days if that.
You're right though, no one asked for this in a monitor, but much much more importantly no one wants this