So I always thought the thing you see through EVF is exactly the picture you get, until I got my first mirrorless Canon R10. Turns out it is not!
The depth of field inaccurate in EVF:
My first surprise came when I tried to shrink down my aperture. The depth of field in EVF wasn't really changing as much as I expected. I thought my camera was broken so I pressed the shutter - I got the exact sharp image as I expected.
I went down the rabbit hole that apparently only Sony gives you the exact depth of field preview in EVF (correct me if I am wrong). Nikon will only change the depth of field until f5.6. Canon maintains the fully open preview?? (really didn't get reliable information so let me know if you have it).
The brightness is also inaccurate in EVF:
I realized if you want to intentionally take a very dark picture, your EVF will boost the digital signal so it appears much brighter than your actual photo.
I mean I guess for people who are new to camera, it is still much closer to "what you see is what you get" and therefore much easier to use than an OVF. But for someone who are used to DSLR this really bothers me. It's neither the exact scene you see as in an OVF, nor it is the exact picture you would get as what I thought EVF was. Am I too paranoid?
For reference, my Xiaomi 14 Ultra has a Pro mode where I can adjust aperture, ISO and shutter. There I pretty much get the exact photo I see on my display.