I've never seen any ads in my smart devices and I have a hard time seeing how the user data could be worth so much that dumb device startups can't even enter th

I've never seen any ads in my smart devices and I have a hard time seeing how the user data could be worth so much that dumb device startups can't even enter the market. Do you have any source with numbers on this? I mean, I can understand the value of user data from Facebook but a stove or a fridge? What exactly are they selling? Edit: realized now we're talking about TVs but still, is that data really worth that much?