My washing machine doesn’t need Wi-Fi.
It's a feature that I would regret.
I just need a way to wash my pants.
Not show them to the Internet.

My oven doesn't need Wi-Fi.
I'd value that least of all.
It's already shielded from getting too hot.
It doesn't need another firewall.

My fridge does not need Wi-Fi.
That is just not useful for me.
I want a place to chill my food.
Not chat via TCP/IP.

@neil Yeah, while I could see simpler protocols being useful for those (like for accessibility reasons or alerts while at the other side of the house or in the garden) internet access there is just asking for troubles.
Including immediate ones as wifi goes really badly through walls.

And in a way see how for consumer landline phones it's either good old RJ11 or DECT, and IP is more on the professional side of things.