There's not a linear relationship between the tests and usability. There are many tests for various character encodings, but viewing a web page means you're onl

There's not a linear relationship between the tests and usability. There are many tests for various character encodings, but viewing a web page means you're only "using" one of them, for example. As such, 90% test pass rate but low usability simply means that 10% of the tests cover a lot of very visible usability features that ladybird hasn't addressed yet.