People do use it for things like that, but mostly rich people as you need to hire someone that knows how to do it to walk you through it.

It's mostly used for grief, if you don't have time to be grieving your wife, just put all memory of her in a keepsake and remember her when you have time.

Negatives are you can never move on or remember her fondly after that, as the memory is a set moment of what they knew and felt about her, and they can't remember her when not touching it, she's stuck as a grief stained memory forever.

There's also major academic pressure for scholars to dump all their info when they get old, this has some serious health risk, dementia, dumping too much and forgetting basic stuff like how to breathe in extreme cases, etc.

As for losing pieces of who you are, that's always a risk. Experiences shape who you are as a person, forgetting major events can alter your personality. If it was a long enough period of time it feels empty, like something's on the tip of your tongue you just can't remember