There has been a recent decline in the steemit population activity.

Yes. Especially after the recent price falls. And as for the spammers, it seems like they have developed their own little communities to make mutual profits without having to make any efforts to make quality content.

If this keeps happening, it surely will reduce the traffic here on Steemit. People won't be able to grab attention for their original content and will eventually leave the platform; and curators won't be able to find posts that are actually worth upvoting.

The biggest problem is, people are not willing to contribute to the problem. They don't wanna flag spams because then they risk getting their own content flagged on by the whole group of spammers.