What is the subject of the following sentence, "Better late than never."
What is your analysis so far, Anon?

(Unfortunately we can't simply provide answers to questions, as they might be part of someone's coursework; but we can help if you tell us your thoughts so far.)

There is no explicit subject.
The context implies a subject.

Tom arrives late.
Mary says 'Better late than never'.
Tom' is the implicit subjectt. Or you could argue that 'Everybody' is the more general subject.