I use Siri all the time for sending/reading text/WhatsApp messages and making calls and setting/stoping alarms and timers, and creating notes and taking pictures (Siri will open the app to where you are a click away from taking the picture. I also use Siri as a dictionary and weather forecaster.

I wish Siri was more powerful, to do things like create contacts and turn of the phone but Apple seems super conservative about what it will allow Siri to do