Is the Sony A7III or Sony A7RIII better?  Both cameras feature greatly superior battery life to the previous-generation’s models.  For video, the Sony A7III definitely isn’t a “base model.”  The autofocus abilities of A7III trump the A7RIII’s auto-focus capabilities.  What the Sony A7III does not have though is as many megapixels and the EVF is of lesser quality.  Are you a “still photographer” or is your primary focus video?  For me, I shoot video primarily but do appreciate high-quality stills as well.  The A7III is the best fit for me.

Available on Amazon.comSony a7R III 42.4MP Full-frame Mirrorless Interchangeable-Lens Camera
Available on Amazon.com Sony a7 III Full-Frame Mirrorless Interchangeable-Lens Camera Optical with 3-Inch LCD, Black (ILCE7M3/B)