Criticism of cherry-picking cuts against WebP because the marketing campaign for that codec relied on cherry-picking both the least optimized JPEG codec and the most favorable metrics for comparison. If you had humans comparing images or enabled JPEG optimization you saw far less exciting numbers for WebP - usually under 10% savings, not uncommonly negative – and there were other formats which consistently outperformed it. You can see the mood around that time here:
Even a decade later, however, Google repeats the 25-34% claim and their performance tools tell developers they should use a modern format, which by sheer coincidence means the one they invented rather than the best ones on the market.
Except the problem isn't in a single image, it is a pattern that is frequently there and the image was only used to demonstrate it. WebP has this problem way back as one of the reason others were hesitant to support it except Google.
There isn't a codec pair in this world where you can't make a cherry picked comparison where one of them is worse (I've done plenty of those).