This is the kind of sentiment I had when people ask me about 日本語 regarding: “do Japanese people memorize all 50000+ Kanji?” I’m like “NO” since they don’t know all characters as only a small percentage of that is taught & used, around 2136. Although, some people learn jargon catered to specific fields (science, medicine) leading to them knowing 3000+ Kanji.
The estimated count for the “number of words” in English is 1,000,000 but that’s not an exact answer. The thing is, how many words is a native English speaker expected to know & understand? How much vocab do they teach students at school (from spelling to grammar)? After learning the alphabet, what types of words are taught across schools in the Anglosphere to kids?
For perspective, kids in Japan only learn 80 Kanji in their first year (mainly common & easy ones: 犬、校、九、女、男、名、森、右 to list a few) but the number expands through their years. I mean, something “similar” exists in English with spelling being taught at schools (teachers give a list of words to memorize spelling followed by a spelling test later).
The vocab lists expand from elementary to high school with difficult words (there’s a difference in difficulty with trying to spell a word like “animal” to “conscientious”). It’s like how a Japanese kid knows how to handwrite 海外 but has a hard time on trying to understand 傭兵 (ようへい) since 傭 is a harder Kanji to write in comparison to 海.
The short answer is, of course, ‘no’. For Japanese, I couldn’t even hand-write all the 常用漢字 without looking at some reference, but I also know Japanese words my native-speaker wife does not just because of medical, legal, and job-based jargon. She, who has a sports education, knows a bunch of other health, education, etc. jargon that I don’t.
Multiple countries have English as a first, co-official, or defacto language. I think it is difficult to paint an accurate picture that covers all of these, let alone if we include countries that have at as an official but minority language (and edge cases like international schools such as exist here in Japan).
You might be able to find per-country education guidelines online (though realize the US also does many things at the state level, so it may differ for every state at least there) which could give you an idea. You could also look at university entrance exams or similar tests to see what is being checked for at that level.