If this were a thing, I would have wasted years of my life learning musical instruments and foreign languages. The reason those skills are rewarding to have is because you have to work for them. My skill levels in these things are a reflection of how I spend my time and who I am as a person. If that was just erased, and everyone could be good at everything, then I wouldn't be anyone anymore.
That's kind of the sad truth of it though, once it is a useful and safe enough thing, you either pay for it or get left behind, it's dystopian as fuck, but it will significantly increase the utility of those who can get it.
Why not? Transhumanism is cool. It would take a lot of convincing for me to be sure that it is safe, but I also roll the dice every time I drive to work or take a pill so whatever.
Because this is all sci-fi woo woo and the honest truth is that we have no fucking clue how memory storage, learning, experience, or recollection actually mechanically work in the mind. At least relative to how an electronic device could interface with, let alone, augment or manipulate those mechanisms.
On top of that, our current system has proven time and again that you cannot trust an entity whose sole purpose for existence is to extract wealth from the resources around it (i.e. people). Not especially for something like this. It will need to be regulated, standardized, limited, and controlled by an external coalition.
Don't get me wrong, there's absolutely zero chance I'd sign up for Elon Musk's shit, but this kind of augmentation is very likely to be cellphone tech levels of disruptive - you'll wake up one day and it's going to be ubiquitous. Nerve interfaces for prosthetics are already becoming commonplace, and cochlear implants even more so. I truly expect that all of this "mystery" is going to be uncovered quite quick once commercial viability is demonstrated.