Non-retrofocus, close to the "thin lens equation", strong wide angle designs (where the light comes in wide angle and goes out wide angle) are known to be tricky and unreliable in their results when used with many contemporary digital sensors, as opposed to using these with chemical film.

Digital sensors can exhibit artifacts like color shifts or loss of resolution in the corners when exposed with light rays coming in at a severe angle, often due to color filter matrices and on-sensor filters offering a different optical path than expected - for example, a color filter "pixel" (being a tiny bit of colored transparent material) hit almost sideways could end up bleeding some light right into the sensor-facing side of the next (differently coloured) filter element, literally undermining the color filtering effect there. If that doesn't happen (eg because whatever is next to the filter pixel acts more like a black baffle), that light might still not be fully registered by the sensor, resulting in vignetting.

Also, SLR lenses may appear shorter because they can outsource some of the bulk to a high focal flange distance body - the same lens on a DSLM adapter that restores the right flange distance will, again, become comparatively large.

...

Addon: IIRC Leitz actually had to do something special to their sensor filters for the digital M models exactly because of these issues...