Honestly I think the only reason you guys shipped as many units as you did was blocking other voice assistants from interacting with Audible. I've had an Alexa/Echo since the early beta and it has literally always been worse than other options like google home. It's gotten progressively worse over time as well. Not just comparatively but vs it's own experience several years ago.
Yep, can confirm that it was better in 2017 than 2021.
Mainly because when the org chart grows, more "rules" are added to the rules engine, where each rule is managed by another service... which all adds to end to end user perceived latency, etc... that's why rule engines don't work.
The hardware is just a microphone, a speaker, a tiny computer, and a WiFi chip. It's easy to keep providing updates for old hardware when all the brains live in the cloud.