My two work-horse cameras are Hasselblad H3D31ii and Sony A7Rii.
Yes, the optical viewfinder on the Hasselblad is better in brightly-lit situations. Outdoors in the sunshine or in the studio with bright modelling lights it yet to be beaten.
But shooting star trails, any manual focus situation, or shooting in a dim studio (eg lit by flash, but where the modelling lights are non-existant) I find the EVF better.
It's not as detailed or as responsive, but it is certainly brighter, provides a magnified view for focussing, zebras for exposure, peaking, etc..
And there's PLENTY of scope for improving EVFs in future generations of tech. The optical viewfinder is never going to improve much, after more than a century of work it is now constrained by the physics. A f/2.8 lens on the Hasselblad gives as bright a viewfinder image as it gives. An f/2.8 lens on the Sony can have the amplification turned up so you can almost see in the dark.
No mirror to slap, electronic first curtain to remove shutter shock, and even better what-you-see-is-what-you-get than a SLR.
I'm starting to prefer the EVF, on balance. Not that it's perfect. God knows it could do with higher resolution and higher refresh rate. But that'll come.
Cheers, Hywel