The effort of learning a different grammar is dwarfed by the effort of memorizing a sufficiently large dictionary to understand everyday speech. To read at an elementary school level you need 5-20k words.
I thought that too, but as a bilingual person who studied Latin for several years... either I'm linguistically handicapped, or the grammar was legitimately tough to wrap your head around. Or both. Some of it was that I really did struggle with the grammar. Some of it was that sometimes we really were reading syntactically complex writing.
That's not true. People usually learn around a thousand words per year. Someone in their 20s is expected to have a 20k vocabulary but much of that is academic or professional vocabulary. i.e. the overlap between a mechanical and a software engineer might only be 15k words.
Is that number for active or passive vocabulary? For active, it seems reasonable, but GP is talking about reading comprehension, i.e. passive vocabulary.
