Both Leica M Edition 60 and Sony A6500 have 24.0 MP resolution sensors but Leica M Edition 60's sensor is Full frame (36 x 24 mm ) and Sony A6500's sensor is APS-C (23.5 x 15.6 mm ).
Since Leica M Edition 60's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Sony A6500.
Below you can see the M Edition 60 and A6500 sensor size comparison.
As seen above, Leica M Edition 60 has a 2.4x Larger sensor area than Sony A6500. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.