every single report by a user matters more as they're sent to every federated instance

For example:
As a user of instance 'a' if you don't like your moderators' actions/inactions, now you can easily jump to instance 'b' which still provides you access to the previous communities that you were subbed to

due to this interconnected complex system, instance admins and moderators are more likely to take reports seriously and attempt to provide their users with the most reasonable services and logic

all of which means that bot accounts are highly scrutinized than regular users

sorry for the long explanation but I hope this helps you understand how and why🤗