Guess what, we don't need an internet of things. It's not going to happen and you can tell that because it's been hyped for a decade now and has not produced any product that anyone buys.
How much cheaper is electricity because meters report back and you don't have to come and read them one by one. How many times has the garbage truck passed by my street only to see no trash container out to be collected? IoT means making everything intelligent so that we can better coordinate our resource usage. A traffic light that knows when the tram is coming ahead or behind schedule, how many people are on it, how many cars are to queue on the red lights can make a better decision on which one should be prioritized, possibly saving a fair amount of electricity in the process.
Or, perhaps, a carpet that knows it's clean (let's say the kids are off to summer camp) can tell the Roomba it doesn't need to do its thing today.
We don't need it like we didn't need cellphones, smartphones, smart watches, electric cars. For most of my childhood we didn't even need personal computers.
My apartment a few years ago (wasn't a luxury place) came with a Nest thermostat. My parents have a Nest thermostat as well as a smart lock. My sister has a smart toothbrush. My friend uses Tile to keep track of a couple of her grandmother's important things. I went all in on Phillips Hue across my house, as well as a bunch of other things. It's not all sunshine and rainbows, but it's been a net positive.
HomeKit (and any Android equivalents) have brought this stuff pretty mainstream, and in a mostly-just-works way.
This stuff is everywhere.
What could there possibly be for a tootbrush to do that would require an Internet connection?