His confidence is key. YouTubers are racing each other in content "the next big Barca star". I think it's early days, that was a game against struggling Valencia. But, yes, Olmo has to up his game for minutes. There's competition.
You can't win with some people. If he hadn't performed (and some retards like Zeni were lambasting him after 15 mins) they would say: "look, he stinks."
If he plays great: "It's only Valencia".
Truth is, Fermin has been performing well for full 2 seasons and now entering the 3rd. He has proven that he's good enough.