I have just created a tournament...

... but it is not visible in the main Arena tournaments page. Why? Thank you.

( lichess.org/tournament/4H58K18E )

Because it's not organized by Lichess and also it's not a major tournament.

Imagine an arena page with hundreds of user-created tournaments that nobody is interested to join ...

@Cedure216 thanks for your lovely answer. Imagine an arena page with hundreds of user-created tournaments where some are interested to join

It's me probably