It's really handy but "Hey Siri" works maybe 30% of the time. I don't really use it anymore. The worst part is that Siri can't integrate with other music apps, other note taking apps, other video players, or pretty much anything. So it's incredibly crippled despite being able to parse my requests.
If Alexa can fix that, this would be pretty neat.
Until Alexa, I hadn't tried Siri since its initial launch years ago. I was surprised to see that its AI/NLP was as good as Alexa's. So the killer feature really is the convenient and reliable interface provided by the Echo's mics.
You answered your own question. Not every device used in a home (remote control, light switch, thermostat) needs to be replaced with a full tablet computer, even if it could be.
An always on dedicated device that lives in one location with excellent array mics is going to be more useful to me than a tablet that I have to locate and turn on before I can use it.
I also had an old Moto Defy I kept for years and years plugged into a wall outlet as a dedicated tune-in audio device. Listen all I want to TuneIn and it wouldn't eat my phone's battery because my old appliance phone was on a charger and my phone was unused in my pocket or whatever. After a couple years on the charger, maybe it was the heat, I donno, the battery bubbled up as they do before they blow up and I got rid of it.
I had a nexus 7 and my kids have had two generations of ipads and there is no perfect stand out there. There are some the fold and collapse when you don't want them to. There are some that hold nicely as long as you're not plugged into charging. There are some that work but look ugly and cluttered. Its a hard problem, apparently. You folks will laugh but my kids solution to the problem of too many devices and not enough space for charging is a device pyramid. I've noticed the main difference between harder-core older computer users and noob/kids is tolerance of dust, grease, and dirt on the screen, so a pyramid of devices on a desk makes sense to kids and noobs even as a more experienced professional who looked into screens 10 hours per day WTFs about it.
Portable is a fail for appliances. I don't want my kids leaving Alexa in a laundry basket or between the cushions in the couch. I don't want to step on it at night. I don't want one more thing to yell at my kids to put it down and go to sleep its your bed time. No one wants a portable surround sound system or a portable toilet or a portable microwave oven. Or even more utilitarian, contemplate a portable hot water heater. A jetboil is nice when I'm camping and drinking my tea but I wouldn't want to replace my houses hot water heater with a jetboil at every sink and over the shower. A portable outside air temperature thermometer is a good analogy where not knowing where to look to see the temperature is not a feature.
Alexa already does more things than I'm interested in having her do. Something that does more is even less interesting than you'd imagine.
Unlike my experiments above, this new thing apparently just works yet costs about the same. I'll take the product that actually works.