Knowing what TV you own, what phone models are used in your house, and what other devices you own tells advertisers about your spending patterns and income.
And can be used to cross-correlate with other datasets to further narrow down who you are and how you can be targetted.
My income is low. Ignore me, advertisers, you have no power here.
I wonder if you can identify the age of devices based just on network scans? Like if an advertiser can tell I've got a washing machine model that was last sold 7 years ago, it's time to spam me with washing machine ads.