One issue that I think is a serious challenge for crypto, as far as wide spread adaptation is concerned, is some type of error-correction. Not necessarily an error in the system, but human-error.
Its one of the things that conventional systems have in place that bitcoin really lacks. I've only been using bitcoin since 2013, and to be honest I still get a bit of a panicky feeling every time I send coins out. "What if I used the wrong address? What if I'm being ripped off? What if the transaction gets stuck? What if there's a new zero-day exploit which drains my cold addresses (yes... I even worry about my cold addresses [
https://lbc.cryptoguru.org/trophies ])?"
People make mistakes. I am fully aware, and really support the 'non-reversibility' of bitcoin, but this issue has been in the back of my mind for quite some time.
I've sent coins to an incorrect address. I think those of us that use bitcoin willingly accept these risks because we understand the alternatives, but I don't think I could live with it if it was inherent in every financial transaction I made. I would hate to worry about my whether my utility payment was successful every month. Or my car payment, or mortgage.
The concept of mis-sending, coupled with irreversablity is really quite unnerving. I have lost coins in exchange melt-downs, and have also come to expect a certain amount of successful theft in crypto. If something is wrong with a product I've purchased, I am left to the judgement and honesty of the vendor.
The concept of purchasing with bitcoin but having no way to recover coins if I have been a victim of fraud is also quite unnerving.
Over the years I have noticed this problem attempting to be addressed, but what I'm seeing is yet another form of banking. Escrow providers were one of the earliest that I saw. We are already experiencing the horrors of mining power becoming concentrated. What would the landscape look like if escrow became big business? What if "bitcoin insurance" came into being (sort of an FDIC for bitcoin)? Coinbase wallets are very popular, with many users of it unaware that they don't control the coins in that wallet.
I've spent a good deal of brain-power ( of what little I have ) thinking about this issue, and every scenario I think of involves some entity wielding huge amounts of power and trust, which rarely continues with both surviving. I am sure this can be addressed in some fashion, but I really am concerned about what that solution would look like. I have a fear that the solutions that actually get adopted (by a huge number of people missing the whole point of bitcoin) could kill the very strengths of bitcoin as a system.
Can the system be safe for people that are non-tech, non-crypto savvy?