Whether the "incredible speaker" part is true remains to be seen since the thing hasn't released yet but you can look at a lot of the features and they're very music-focused.
It's more competing with a Sonos than it is with an Alexa in my mind, the Siri stuff is just lagniappe.
Incredible by what standards? It's not even stereo. Nowhere does it mention perhaps the most important metric for audio quality, namely RMS audio power output. The tiny size alone pretty much guarantees that the amplifier will suck.
I'm very confident that e.g. a combination of Klipsch R-15M speakers, Yamaha R-S202 amplifier and a Chromecast Audio will knock its socks off. And that's a setup which you can order on Amazon today, it costs exactly the same, and it can do perfect multi-room out of the box.
The current breed of class D amps are shockingly small and and have pretty decent audio specs(thd, rms, etc). Unless you are expecting a 50lb analogue >500w audiophile quality amp, I’m not why you would assume the size == low quality.
So the idea of just having a single device that automatically integrates with your phone, etc. is appealing to many people.