Only 4K resolution?
What camera are you using?
I agree the B&W is really monocolor instaed of B&W and it is way short on mid-tone contrast.
The lack of mid-tone contrast is hindering the perceived sharpness of the photo.
I see here about all smaller images, than this your "only" is curious......
here i used a 36 mp camera (Sony a7r). I use to prepare, see and evaluate my jpgs at 4K resolution, then this is my
"target" file and I like to present them so.
About the "lack of mid tone".....ok, but I like to preserve detail (and I think it's good, or not, in the 4k visualization?) but without that kind of harsheness and dry/simplifying strong contrast of many digital images we see.
Then I like (for this kind of "old-fashioned-but-detailed-image-warm-toned" to increase micro-contrast holding, or subtracting something as here, some points to general contrast. Half tones are imho more important......
My reference is Large format film and prints worls, and I try to stay near to that world (I too use really LF cameras, but with digital I have less weight to carry on my shoulders.....

Thank you and all the best,
sandro