By creating sockpuppet accounts, you can fake more activity in discussions. This encourages real users to participate. Repeat until there are enough real users to sustain a community without sockpuppets.
Reddit did this, as they said in this interview. Others confirm the approach.
No.
To expand on this: No.
It’s an immoral, disingenuous practice employed by corporations in their quest for rapid growth to attract venture capitalists. We do not require growth.