Yes, this effect has prevented me from even being able to use the product subscription services Amazon has tried to launch. I might get one or two periodic shipments but then I'd hear "Oops, that product is discontinued." Turns out it's still around, just in slightly different packaging, or with a new brand tweak. In the end the uncertainty and reliability and hassle are all far worse than just remembering to buy myself more shave gel and toothpaste at the store when I start to run low.
But given how hard it is to even find just standardized products on Amazon at a reasonable price and with Prime shipping from a reliable seller, etc, etc, when I can _see_ what's going on, I personally would never trust Alexa to do the selection for me.
In another situation, I had a subscription for one product that was $32 when I started subscribing and I just cancelled it after noticing that the price has risen to over $50
But given how hard it is to even find just standardized products on Amazon at a reasonable price and with Prime shipping from a reliable seller, etc, etc, when I can _see_ what's going on, I personally would never trust Alexa to do the selection for me.