Not talking about comics, rather on books (like actual novels containing chapters consisting of only words). They say that both French and German are “closest” to English but still different languages, however even if an English speaker were going to learn either language, does it mean can they understand written text from books or is that hard even with cognates?
It depends on the genre of the reading material, also affects difficulty regarding vocabulary. Such as: thriller (crime): has terminology, uses expressions and bundled in sentences that are beyond A2 level proficiency while YA (teen) may be written within a beginner lens. This is not the same as reading a sign in French as a English speaker as books have blocks of text.
Even in the reverse: what is the recommended level (from A1-C1+) for a non native who is learning English as a second language to read an entire book (like those written by Lee Child, Agatha Christie) fluently with understanding not only the contents written but infer on the novels concepts and relay reading comprehension akin to a native speaker?
i recommend trying to read books made for children or adult learners as soon as possible, because it’s a great way to pick up vocabulary. that can absolutely be started at A2 level, although you’ll need to look up words for context fairly regularly.
B1 level is generally when learners can start reading YA-level novels without stopping too often to look things up, because their vocabularies will be good enough that they can start to infer things from context.
B2 would be about the level for a lee child / agatha christie novel, although specific terminology, less common grammatical structures, or dialectical speech will still likely throw you for a loop until you encounter them more often.
i believe C1 is when learners are getting closer to that native-like fluency with reading comprehension etc, but i’ll let you know when i get there! :P