It has absolutely happened with those things.
Cars: https://www.youtube.com/watch?v=sceLsLkQf7A
Fridges: https://fortune.com/2025/09/19/samsung-family-hub-refrigerat...
I'm not aware of a smart watch doing first-party ads yet.
The existence of a single crappy car does not mean all cars are crappy
I didn't list fridges because I've seen ads there, but these seem to have gone away in newer models (people don't like ads)