I dunno. I managed to meter correctly nearly every time back in the day, even silhouetted subjects against bright backlight, and even using transparency film with maybe five stops of dynamic range (instead of 12 or more from my Pentax), and even with no possibility of correction prior to display. My old Canon F-1 had a useful center-spot meter good for that purpose, and better (for anyone who understood zone placement) than the center-weighted metering used by Nikon. That was before multi-zone metering, which was a feature on my Canon T90 (a lovely camera). I still use an external meter for big film cameras, of course, even though I have the metering prisms for my Pentax 67s. For large format, I use a spot meter, but I don't do a lot of filtration or long bellows macro extension that would require a lot of mental math (though I do know the math).
Rather than letting a screen tell me if something is exposed correctly (which I absolutely do when using, say, my iPhone), I can just point the meter spot on the part I want to place at middle gray, press the AE lock button, recompose, and make the photo. I do that anyway because I set the camera to only use the center focus spot, and I focus and then recompose unless I'm using a tripod. Or, I can depend on the multi-zone metering in the camera that will seek to prevent any one zone from falling outside the characteristic curve. You know--tools that have existed to solve this problem for decades; tools that iPhones don't have. I don't think any of that is slower or less accurate than using an electronic finder to check exposure.
For me chimping is about checking the expressions of the subject and to make sure everyone's eyes were open. For non-moving subjects, I rarely chimp more than a quick glance at the held image before it times out.
Rick "a matter of technique" Denney