The problem is, you can never beat some aspects of an OVF with an EVF. How are you going to improve on zero lag, zero power use, virtually infinite dynamic range and color gamut?The human visual system already has lag, and some EVFs are getting quite close to human lag. I think lag may be one of the first impediments to fall.
As for the DR and color, that's precisely why I want an EVF: I want to compose using what the sensor can see, so I have a better idea of the final image. This is another plus for EVF.QuoteEVFs suck power like crazy. You're going to need a battery breakthrough to replace OVFs as well, or an enormous battery that more than makes up for the size difference of removing the prism and mirror.Yup, this one is still a real problem for event/action photographers. For landscape/studio not so much.
Until you take that evf into very low light. Then It shutters and flops around like a fish out of water. (With the a7 anyway.)
For now, but it's not an intractable problem. I'm not saying mirrorless replaces OVF completely right now, but it's definitely heading that way.