The key differentiating factor in your hypothetical reasons why traditional finance is inferior to defi is that there are systems to remediate the exact issues you mentioned, whereas if you send your crypto to the wrong address- it's gone. If you lose your seed words to your wallet and can't access it, or someone else gets access to them- it's gone. If you get scammed- it's gone. Literally all of these things (which are a /feature/ of the tech!) make it essentially unusable for any business that isn't looking for an adrenaline rush. What I love most about all of these shortcomings of the technology is how much people who push it minimize all of these issues by saying that it's user error, and people who utilize good practices won't have these issues. It's almost as if all of these people have literally never talked to a real person. No regular person cares or would ever want to care about hard wallets versus alternatives, seed words, verifying addresses, and avoiding phishing scams. All of these issues which can be mitigated by being technically inclined fall flat on their face with any person who just wants to send money to their grandson or pay a friend for dinner.