Why does Vue.js linter swear?

Question

JavaScript

There is a function

And, accordingly, data

Linter swears, the question is why?

Answer 1

You declared it in one area, but do not use it there, and in general, you declared it - why do you need it if you do not use it in this scope? Here's a linter that says to you: "Think about it, Fedor, you're a dumbass."
In general, this variable is not needed in the current code, and the linter tells you about it