IMHO, you're not missing much. If you tend to push the exposure away from the metered exposure for creative reasons, then being able to see the result in the EVF is a benefit. And it can help you catch metering errors when that occurs. Otherwise I don't find it to be much of a benefit. Most of the time there's very little difference between when I have it set for showing the exposure vs adjusting for ease of view (more like optical viewfinder).
And as far as AF speed/accuracy, etc... I don't find it to be hugely better than the D5/D850 is/was. I was expecting more, and now I mostly wonder what the others were doing wrong that they find the performance so revolutionary. Sometimes I find the AF to be more prone to error, i.e. grabbing the BG and refusing to refocus nearer. And trying to photograph a chimney swift in flight is still just as frustrating.
Mostly, I just take more images than I want/need because it's set to 20fps when 10 would be more than enough.
Overall I would say that there are incremental benefits; and a few more when combined with Z lenses. Silent shutter (or set nearly silent) can be a pretty big deal with some wildlife and event photography.