Of recent purchases on Amazon (sold by others, but dispatched and warehoused by Amazon) 50% have been faulty and needed to be returned ... that's put friction into the process because they don't do any QC on what they're stocking.

I've also had an instance recently of something shipped by Amazon that was meant to be with me next day not turning up and needing to be re-ordered. They only admitted it was lost days later, so I didn't re-order sooner. OK, I got a free month of Prime for my troubles, but it's not the amazing friction free experience it used to be.