A while back, I compared my digital mirrorless Canon to my last phone.
Wasn't better in normal light.
In low light it was, since the lens is so so much bigger.
And it has the very pixellated viewfinder.
I think I'm going to hold on to my dSLR for a long time. I might just be old fashioned, but there's just something about a through-lens optical viewfinder that I feel can't be replicated digitally.
Even if you wanted to create a digital viewfinder scope, by the time you put in the optics to make it feel real (and not feel like you're squinting at a small screen two inches away from your eye), you've taken up nearly the same amount of volume as a traditional viewfinder, so you might as well have a mirror, too (almost). ;)