97% of the worlds currency is... digital.
Probably 90% of your Federal Reserve notes are digital.
If someone were to hack your account at a bank, they could steal all your funds, digitally. This account is held at 1 bank, with 1 set of security parameters.
Bitcoin is open source, anyone who wants to see how the program works, if they want to, can. Every Bitcoin before it's traded must be validated by "miners". Therefore, the accounting system is double, triple, a ridiculous amount over checked. Every transaction, checked and validated by the public.
Ok soo...A small group of accountants at a bank or +100k bitcoin owners whose best interest it is to keep their investments sound...hmmm.