Think about this way: They subsidized the hardware and hardware development too much and created a messy third-party ecosystem rather than focusing these 25 bn USD on developing an AI chat (OpenAI spent less in total).
Alexa came out in 2013, long before transformers (2017) or chatgpt (2022). The state of the art back then was closer to CleverBot than anything useful.
We will likely have decent standalone voice assistants at some point soon but Alexa and Siri were way too early for that.
