Another issue is punishment. Ideally, if a particular user paid a bot service to add 100k new followers to their profile, not only the bots but the manipulative

Another issue is punishment. Ideally, if a particular user paid a bot service to add 100k new followers to their profile, not only the bots but the manipulative user should be banned. But there's no way for Twitter (or any other platform) to determine who's actually responsible. "False flags" (framing a user by buying followers for them, or running bots themselves to follow them) are not uncommon, so the best Twitter can do is remove the followers and improve bot detection capabilities. This lets users continually pay for more bots to replenish their periodically purged follower count.