As you already hinted at and many commentators rightly pointed out the problem is users posting pictures/videos/articles that is not their own original content. Now if someone shares a vid/pic with some sort of qualified explanation why this might be useful to others and credits/links the original source fine.

All others instant delete, at least in those cases where you can be 100% sure that it's not original. It spams the entire entry list. At the beginning I was really thinking about how to credit images I used (probably less than 1% of my posts contain an image/video that's not my own and that is usually for a reason) and then I realized no one seems to give a shit and worse it gets resteemed/upvoted.

Serious issue here no doubt! Thanks for highlighting this!

You now got my vote which seems to be worth more than yesterday :).