A simple timer that switches off after a couple of hours would do. The timer could reset every time the oven door is opened. This should solve most issues. Long cooking could have a bypass button or somethong (if the door open reset is not enough).

Even if you left the oven on, I believe it’s very unlikely to burn down the house.

These devices are designed to work for hours with minimal supervision. Given the size of the user base, IMO ovens are extremely reliable. And electricity prices are too low to be anxious about the costs.

That'd be a legit feature, but far less involved than a full-on smart oven. At most, it'd have a way to turn off the oven remotely (but not turn it on).

Anyway, last time I had this anxiety, I checked my Ring camera in the kitchen that's posted there for reasons like this. Works for the stove and faucet too.

If you think the oven can burn the house down, how about the anxiety of trusting some companies IoT oven not to be exploited by script kiddies to burn your house down?