The downvoting is a feature that is meant to help
Reduce spamming on steemit because the downvoting was created as a feature which someone can use to downvote any post which they feel is of low quality or it is like spamming post

But these days the issue is that some people now downvote for no good reasons,some just want
To downvote people just to make their own content trend more than the downvoted content
There are spammers now downvoting for no good reasons,they just downvote as a way to hurt others or just do it for fun

Downvoting even become more effective when the person downvoting have huge steempowers,i have also seen some whales on steemit that downvote each other especially contents on the trending page of steemit