Is this a copyright violation?
Nah, not if they’re the only screens in common. All designs share common elements, these just both use a similar background image, if that image was changed, maybe 50% of the similarity would be removed.
I think you need to add 30 more screenshots of other themes from ThemeForest and hundreds of sites all over the Internet. And who was the first to create such Hero Section?..(it was a rhetorical question)
It depends on a lot of aspects. If this is just related to that section, and the code is different, I would say no.
If more elements share the same similarities, then yes, inspiring is one thing, copy and pasting with small incremental improvements is another.
From what I see in the demos of the screenshots you posted ( PS: I had to remove them as it’s never a great idea to bash other authors, even if they’re guilty, let support handle it ) it doesn’t seem to be copied.
Sure, their styles do look similar, but the internal components and pages don’t look the same. However, if you have doubts, ask the opinion of a reviewer by getting in touch with Envato Help and Support