> First, you don't need 10k kanji to read. About 3000-5000 depending on what you read is enough.

You’re still grossly over-representing what is needed to read Japanese.

1. 10k characters is utter nonsense. I assume that people conflate the 10k words needed for JLPT N1 with characters. They are totally different, since words are often combinations of characters.

2. Joyo kanji has 2,136 characters. All government documents and pretty much all mainstream media use only these characters plus some kanji specific to names. Any kanji outside of joyo (e.g., an unusual name or a stylistic word) typically have a phonetic reading (furigana) next to or over the character(s). Joyo is what is tested for the JLPT 1 (the top level).

3. Hundreds of joyo kanji are very context-specific — that is, they are relatively low utility.

4. There are a few additional kanji outside of joyo that are widely known. Educated folks also know more than joyo that are specialist terms or stylistic words. It would be like an English speaker knowing words like “deoxyribonucleic acid” (DNA) or “ceteris paribus”.

5. Lastly, for anyone reading Classical Japanese or historical documents… well, much of the above is not relevant due to changes in the language (mostly simplification over time). It depends on what is being studied or read.

6. 3000 kanji nets someone “highly educated native speaker” status — think teacher, doctor, lawyer. 5000 kanji gets you nerd status — think professor or logomaniac.