It is necessary in many situation

Sometimes, especially when your post isn't getting much attention or upvotes, giving your own post an upvote can help make it more visible to others. It's not about being arrogant or seeking attention—it's more about helping content you believe is good reach the right audience.

If you believe your post is useful or interesting, there's nothing wrong with supporting it yourself. What matters is being honest with yourself about the quality of the content.