You don't see anything in a raw file until it has been processed. What you see then is only one of a near infinite number of possible interpretations legitimately derived from the information in the raw file. There's no such thing as an unprocessed or unedited raw file displayed on a screen. If you're not selecting how the raw data is being converted to a viewable image, then whoever wrote the default development profile has decided it for you.
That's basically exactly what I said, but it feels like you disagree or misinterpreted my message?
To maximise image quality one should maximise the information in raw file, and maximising the exposure is one of the tools.To maximize image quality, one should maximize the amount of light falling on the sensor until just before the highlights begin to clip.
If it isn't possible to do that at ISO 100 (because, for example, the subject is moving and the light is dim), then the best image quality for a given amount of light entering the camera is the *highest* ISO that doesn't allow clipping!
Generally it's best to use ISO values where the camera uses the analog gain. For Canon R5 it's ISO 100 (base) and 400.
It's not practical for action/sports though.