Questions & Answers about Летом под берёзой мне хорошо читается.
Because this sentence uses an impersonal construction.
- Я хорошо читаю = I read well / I am good at reading
- Мне хорошо читается = I read well under these conditions / It’s pleasant or easy for me to read
So читается does not mean that the speaker is talking about their reading skill. It suggests that reading comes easily, feels good, or goes well for them in that situation.
This kind of Russian structure often describes a person’s state or experience, rather than a straightforward action done by a subject.