2- Users controls there private keys so no fear of exchange hack and loss of funds .

This is not always true. If you hold Open.EOS for example on Bitshares, then OpenLedger has your keys. You are trusting OpenLedger not to get hacked. The rule is if you have your keys, then they are your coins. Go and find them to make absolutely sure because it is not always the case that decentralization = you have your keys.