They did a good job with shopping and music (and timers and junk) but even today Alexa is still far from a full personal assistant.
Amazon should've launched an email service: forward or CC alexa@amazon.com and have your assistant keep track of it. Flights, meetings, reminders, even just responding to emails. The voice-to-text transcription is excellent but so underutilized.
They introduced device to device calling, but as far as I can tell true VoIP never showed up -- why? This would be a killer feature.
Podcast and ebook support was always such a mess and clearly an afterthought.
Amazon's devices were clearly always sold at cost or at a loss. Maybe there's a universe where this is anti-competitive, but there was nothing substantial ever there.
They hired like crazy, but for what? Why doesn't my car have Alexa built-in? Why didn't they obliterate Sonos?
I wish I could use Alexa as a personal assistant, but it never really materialized.
My best guess is that leadership and product vision really, brutally fumbled here. I don't think they knew what they had, and were unprepared to harness its true potential.