Do you think, its worth using the bid bots, given that now most of them are giving max 15% ROI with a possibility of loss as well ? ?

A bid bot should not have the only purpose of earning steem. It is a way to promote your posts so the risk of a loss is fair.

If you find it worth to use a bot depends on you. There are quite a bunch of them and some of them promise to be profitable and with some you have a chance of a higher ROI but the risk of a loss as well.