Being small and light is the main difference between the D5600 and the D500/D7500.2) the D5600 and D500/D7500, the D5600 contains the Exceed 4 processor for which provides 24.2MP providing a slightly higher resolution when compared to the 20.9MP Exceed 5 processor.

Using the DPReview.com's Studio image comparisons, it is evident the D500 (or the Exceed 5 processor) can take the same image I can with producing similar noise at 1600 ISO, but at 3200 ISO and while under similar lighting levels.

DPReview.com's comparison Studio Image, the D5600 (having the Exceed 4 processor) provides slightly better detail resolution in comparison to the D500/D7500 (for which uses the Exceed 5 processor), the higher resolution likely due to the D5600 having a 24.2MP CMOS sensor versus the D500/D7500 20.9MP.

The D500/D7500 using the Exceed 5 processor provides slightly less noise at higher ISO levels, but at the expense of less resolution due to the D500/D7500 Exceed 5 20.9MP sensor in comparison to the D5600 Exceed 4 24.2 MP sensor

As such, the Exceed 5 processor can likely take adequate less noisy images at half the amount of light I have at previously mentioned low interior lighting levels.