I have no issues with Siri's current features. I interact with her dozens of times a day on my wrist, phone, iPad, Mac and soon HomePod. The devices plugged in are far better than the mobile devices. Siri on Apple Watch Series 2 is almost unusable it's so slow but i still use it to lock my doors and turn the lights off for bed.
I would love to do more with Siri. I don't ask it random questions about sports. I want to be able to ask her to send a list of reminders to a shared note with my GF or schedule things and email the right person an invite on the correct calendar or tell my colleague I'm running late with an ETA based on driving time and location of the person (find my friends) synced with my location for A to B route. I want instant translation features so I can understand what my French Canadian friends are saying in real time and being able to speak out loud app store reviews or acquire music and add it to a certain playlist, access my amazon cart and apple store cart app, check in on Foursquare, book mark a yelp location or book me a table somewhere.
A lot of this is 3rd party integration but I should be able to spend an hour talking to my Mac and doing everything without touching a mouse. I'd be fine if IOS 12 is ONLY making siri amazing. I have no idea what Alexa and Google Home are capable of but Apple's 1st party integration should mean everything they want to sell me should be fully voice enabled without any gaps. The fact my mac can't lock my doors or change the temperature in my house is dumb.