I have set timers with Siri 100's of times. It's practically the only thing I do with it. Hasn't failed me once.
Just yesterday, though, I said "Hey, Siri, navigate home" and that literally got into a failed state. The first time I did it it told me I didn't have a "Home" contact, so I made it. Didn't work when I was in the car yesterday, but it did just now. So, I agree, there are issues with Siri.
And there's also the issue that it doesn't seem to have any concept of priors. Every now and then I give Siri (and Maps) a try, and it's always something like, I ask it to "navigate to [name of local business]" and it starts navigating to a business with the same name ... but 2000 miles away. Even though it does have that business on the local map...
Context is what’s missing. A dictionary of recently referred to entities. Most recent person, most recent place. Also things like current location. Am I home, am I moving, etc
Just yesterday, though, I said "Hey, Siri, navigate home" and that literally got into a failed state. The first time I did it it told me I didn't have a "Home" contact, so I made it. Didn't work when I was in the car yesterday, but it did just now. So, I agree, there are issues with Siri.