Have you watched the Black Mirror episode in question (S1E3)? Because the point of it was the tech itself and had nothing to do with sharing or the cloud.
An extremely similar take on this, that predates Black Mirror, was in some sci-fi media whose name, appropriately enough, currently escapes me. Their premise is that there was a species who evolved to develop a flawless memory. It's a subset of the Black Mirror episode (and this dubious idea) because there, at least, memory is a purely private thing.
Yet the end too was quite predictable and logical -- frequently destroying those of this species simply because your own life and mind ends up becoming more tempting and destructive than even the most enticing of drugs. One could simply lose themselves in your own memories. What need is there for the rest of your life when you can simply endlessly relive, in perfect clarity, the best moments of your life - ones that you, in many cases, will likely never surpass?
> What need is there for the rest of your life when you can simply endlessly relive, in perfect clarity, the best moments of your life - ones that you, in many cases, will likely never surpass?
Even without perfect memory, this can still happen, especially if something like PTSD is involved. I myself have a dissociative disorder and sometimes it can be difficult not to just relive the past over and over. (It's not like this is a daily struggle, but during low points it comes up.)
IMO that is a more fundamental argument about removing information from the anxious and jealous who cannot handle the truth. Similar to medical paternalism where the doctor has to decide which test results to tell patients about. Which I understand, but can also be used to go full ham into china style totalitarian censorship regime for the 'peoples own good'.
Also you might not realize how much the hard of hearing, deaf, and other neurodiverse ADHD types would find a memory prosthetic like that very useful unless you are in their very own shoes, for possibly years.
