So if someone had 10 steem at hand, they probably just have 3-5 in hand after using bidbot.

Not always the case. There are some services out there that some bid bot users among many other types of individuals use that allow them to set beneficiaries of the post to the service. In return when the post pays out they charge a small fee and send the payout as if it where liquid to the author. The service than down power it themselves. If someone is turning a profit that 10 soon turns into more and it snowballs till they get flagged or cash it out.