Steem or SBD in Steem's blockchain online wallet is advantageous for two basic reasons: the first reason is that the more tokens you have in your wallet and the more voting power you hold, so more bandwidth on the blockchain and more influence on voting. The second reason is that keeping steem in its portfolio encourages users to take part in the steem ecosystem and to be part of a major dissemination and information project, especially to attract new users to the platform.