I use Siri for almost every task that doesn’t require me to physically look at my screen, e.g. reading, watching a video or typing. The #1 and #2 problems I have with Siri recognizing my input are in order: the quality of the mic I’m using and the ambient noise level in whatever environment I’m in. The #3 problem is the quality of my network connection because it won’t work if it can’t contact Apple.
In my experience, AirPods are the best Siri input device I own. EarPods are a distant second, and the built in mic on phone is a not very distant third. It is effectively unusable on my laptop’s built in mic.
The ambient noise basically means I can’t use Siri in noisy places, and I’m typically not inclined to. I might raise my voice a little if I’m putting in a podcast outside and it is windy.
#3 means disabling WiFi when I leave my house, until I’m in a location with a solid WiFi connection, in part because I make use of my cable WiFi. If I have no service and no WiFi then I have no Siri, not even to set a timer.
Beyond that, I find the basic feature set adequate, but not comprehensive. Siri shortcuts doubled Siri’s usefulness and I only use them for three or four apps.
That said, I appreciate Siri’s presence because it does enable me to leave my phone in my pocket a lot more than I used to, so there will occasionally be a week where I didn’t spend more than an hour or two looking at my phone’s screen the entire week (not per day, per week), with 90% of this time spent reading a book. Observing my friends’ obsessions and work habits, I appear to be the outlier in that regard.