In article .com,
Savageduck wrote:

I never understood well why a digital camera needed a mechanical mirror.

Digital cameras never did need a mechanical mirror.

slrs do.

It just made sense for the SLR manufacturers to engineer their analog systems
for digital conversion, so most of their development for the last 35 years
had them thinking mirrors. Unfortunately for them Olympus, Panasonic,
Fujifilm, Sony, and even Hasselblad leaped ahead in MILC development.

except when physics gets in the way.

That
left Nikon and Canon trailing by at least 3 years, and Nikon has the
additional issue of having to workout a fix for making legacy Nikkor glass
work on whatever MILC they eventually release.

it's a different segment.