My Case for the X-E4 over the X100VI
As previously mentioned, I own both the original X100V and the X-E4. Still, I always find myself picking up the X-E4 more often for one simple reason — the ability to use different focal lengths.
Yes, before you say it, I know that the X100V and X100VI were designed to be a single 35mm focal length; that is the whole point of the camera. But limiting yourself to one focal length is not for everyone, and even if you might be okay with that right now, it might not be what you want later on. That was the case for me. I owned the X100V before the X-E4, and it was great shooting at the 35mm focal length, but then a global pandemic happened. Street photography changed because fewer people were on the streets, and you couldn't (or didn't) want to get close to anyone. The 35mm focal length wasn't cutting it for me, as I felt too far from all of my subjects. The X-E4 offers a similar experience to shooting on the X100V but with the option to use any focal length.
Contrary, this isn't to say that the X100V is a lousy camera in comparison; it's just not going to be for everyone. If you're pondering between the two, I think it comes down to the interchangeable lens question. Do you want to use other focal lengths? Choose the X-E4. Do you want to simplify your process and only shoot at 35mm intentionally? Then the X100V might be for you.
I still think the X-E4 is a better option, even if you wanted to shoot 35mm most of the time. I say that because you can still create the intentional challenge of using only one focal length with this camera without sacrificing your creativity in the future. Secondly, you can make the same compactness of the X100V by equipping Fujifilm's 27mm (40mm Equiv.) pancake lens on the X-E4.
The X-E4 opens the door for much more versatility, which is the best way to describe this camera. It's a camera that can do much and fit many types of photographers' needs. Do you shoot portraits? Its fast face/eye detection AF and non-intimidating appearance are outstanding. Do you shoot landscapes? It's incredibly lightweight to carry on hikes or while traveling. Do you shoot street photography? The color rendition, portability, and overall aesthetic are perfect for any street photographer.