Accounts being managed by bots have one major advantage — it works on autopilot without you manually carrying out tasks. This enables you to follow/unfollow a lot of users and even carry out other engagement activities such as likes and comments without you doing it.
However, accounts being managed with bots are easily identifiable as the engagement level with its content is not as high and as genuine as that of accounts being managed by real humans. However, managing accounts manually can be tiring, tasking, and boring.