The comparison is not very sophisticated. It's like looking after the hairstyle of 100-m runners and saying who will win the race. Although the shape may have an influence on the time none of the runners had cut their hair because of that.
Two things:
OOC-JPGs:
Each camera set a certain style into the JPGs. The reason behind is quite simple. If the jpg would be colour-accurate no one would ever use it and it would be only usable with perfect light conditions. Therefore they have to process it in a certain way that buyers see as pleasing. Currently, it's a contrasty and high vibrancy look with a small green hue range. Brights getting pushed but also compressed on the top. This may change over time. For example the OOC-colour complainings about the II-series (greenish tone) went into the a9/a7III/a7RIII.
Accuracy:
There is a generalised understanding of a dE value greater than 1 the difference is getting visible. Below it's not. If we look at the values on these comparisons it's obvious none of the brands had accuracy in mind when they programmed the algorithms for the OOC-JPGs.
The first question here is what would be possible?
I spent hours and money in the last years to get an answer to that question: Let's assume my setup for profiling my camera (a7RII) was perfect then my best approach to get an "accurate" profile was with an average dE of 0.8 and a max of 3.6. This with a combination of two targets with very different (and many) colour patches. Here is a "similar to the article"-visualisation of one of the used targets (the point in the center is the reference, the rest of the patch shows how my profile render it). It's the accurate profile with a slight push of the darks. I'm too lazy to look after the fully correct one atm.
View attachment 136741
How practicable is an "accurate" profile?
Well, I never use it. The reason is behind the RAW data. Light (colour, dynamic range, haze, ...), hardware (esp. sensor), software (in camera but also raw-processor) are in a play all together. There are some limitations due to the used hard- and software but the biggest issue here is that the result looks not how my imagination sees it when I press the shutter. And creating my look with the adjustments of the raw-processor is just a lot of work. Well at least with an "accurate" profile. It's the reason why I started to tweak the profile in a certain way. And yes in general, my changes goes to more contrast and pushed brights that are compressed on top. Especially the compressing of the brights is a very important step because differences of dynamic range and saturated colors needs very different adjustments. It's much easier if you just compress them. It's something you can see in the profiles of LR and C1 as well (unless you use a "linear scientific" curve with a "accurate" profile in C1).
Don't ask me about the dE of my tweaked profiles. I don't care because the "accurate" profile may be a good start for creating a profile but the adjustments give the profile it's useability and a certain style. Like it is with the OOC-JPGs...
