I do.

If my phone's in my pocket, it won't hear. If it's in my bag, it won't hear.

Or it sets the timer, but then a kid grabs my phone for something and leaves it upstairs were I won't hear it.

There's something to be said for a voice-activated timer in your kitchen that is always in your kitchen and never leaves your kitchen.

That the oven timer is oven adjacent seems a must.

the timer on my phone stay with me. put something in the oven for an hour, I won't be in tbe kitchen an hour later but my phone will be with me telling me to go to the kitchen