View>Display Performance>High Quality
As Bob wrote is the Display Performance.
But why would you use PNG in InDesign? If the file comes from Illustrator use AI or PDF, if the file comes from Photoshop use PSD, PDF or PDP instead.
Nothing wrong with PNG for EPUB or DPS and they print fine as long as
they’re saved properly.
PNGs have a potential color management problem because InDesign ignores their embedded profiles, You could get around that by making sure the assigned profile in Photoshop matched the assigned InDesign RGB document profile (and sync'ing Color Settings doesn't necessarily do that).
An exaggerated example would be a png with a ProPhoto embedded profile placed in an sRGB ID doc:
Problem is, if an helen has as original an AI file, why should she rasterize the file to place it in InDesign. The quality of the original AI file is superior.
Other problem, if transparency exists other than reduced opacity, it would not survive in the resulting PNG file.
Or any CMYK original file will result in a RGB file.