2FA is what I believe should be a standard process for all your IMP accounts.
In today's world where hackers can get access to your passwords using keyloggers, 2FA protects you.
Their is no formal registration that you are the owner of a Bitcoin wallet, therefor legally you can not prove / very difficult to prove that you own the bitcoins on the account.
For your bankaccount however, there is formal registration. Probably linked to your full Name, social security number and/or Passport; you can never question the ownership of the account. (e.g. if I ask a Bank to verify the owner of a Account, they can do that)