Earlier quoted context omitted.
I think that this metric correlates well with the browser being usable on real websites Also, I don't think that the Ladybird folks are just doing the bare minimum to only increase their score on WPT. They're implementing each feature in such a way that basic browsing seems to work better and that their WPT score improves.
The wpt score is not that well balanced. Look at https://staging.wpt.fyi/results/?product=servo&product=ladyb... : out of about 2 million tests, more than half are for the "encoding" category. Good encoding support is needed for sure, but likely not at that level of prevalence.
However, a jump like that means precisely and exactly what I said it means; very suddenly, that metric became much more important to the team. It is written straight into the graph.
A large number of encoding-related tests that were probably relatively easy to fix in bulk is certainly a plausible explanation.
A lot of people are imputing to me assumptions that they are bringing to my post, such as assuming that such improvements must be fake or bad or somehow otherwise cheating. Nope. Moreover, if you are thinking that, don't take it up with me, go take it up with the graph directly. It's not my graph. I'm just amused at the spectacular demonstration of Goodhart's Law.
Are the commentators who think I'm being critical of the Ladybird project going to defend their implicit proposition that the browser got twice as good in whatever period that graph is in, a week or a month or whatever? Of course that's not the case.