Even if they were here on earth (or close to Earth), why would they

use

radio when they have a better method?

You are assuming (with a notable lack of evidence) that there is "a
better method" and they have it.

The SETI search is for ET's living on planets by other stars, not for
ones "here on earth". Consider this: Even if ET had interplanetary
spacecraft, most of their population would still be living on (or
near) the home world. It is also likely that if they had developed
advanced technology, they would also have developed and used radio
frequency communications. That's what SETI is listening for.

CM