Nikon D7100 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor . On the other hand, Nikon Z50 has a
21.0MP APS-C (23.5 x 15.7 mm ) sized BSI-CMOS sensor and features Expeed 6 processor.
Another similarity between these two cameras is that both Nikon Z50 and Nikon D7100 sensors lack anti-alias (Low-Pass) filters. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the D7100 and Z50 sensor size comparison.
Nikon D7100 and Nikon Z50 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.