I agree, but it depends on the simulator you're using.
XP11, for example, has never been realistic in its imitation of reality.
This sim's graphical flaws were so numerous that the use of Reshade was practically mandatory.
Here's an example of the benefits Reshade introduced in XP11.
The first image (XP11 without Reshade) looks like it was captured by a "pocket Polaroid camera".
The scene appears very flat, lacking dynamics, with little sense of depth, and the colors aren't beautiful.
The second image (XP11 with Reshade) looks like it was captured by a "professional Canon camera".
The scene appears alive, dynamic, with a greater sense of three-dimensional depth, and the colors are very similar to how the human eye would see them.
So, Reshade is an excellent tool if used with good taste.
I've always used it in XP10 and XP11, reaping enormous graphical advantages from both simulators.
With XP12, however, I don't use it because XP12's overall graphics are already good and don't necessarily require any further processing.
The graphics can certainly be improved even further (Laminar knows this) and will improve them in the future, but personally, I think XP12 is already very well-balanced in terms of overall graphics even without using Reshade.