5760x3840 is twenty-two megapixels. That's plenty. The PPI value is meaningless.
However, it might indicate that your files are jpegs? If so, that would be very bad.
Good. So there is no actual problem with the file, apart from the fact that you have neglected the noise removal. Please never neglect that, ever.
Please do it now, then tell me if the "problem" still exists when you open the file into Photoshop.
We need to be very clear about this ...
... or no difference at all?
It's most likely that they're identical between ACR and PS when both are viewed at 100%. But I need you to confirm that before we move on to the next part of the discussion.