There is no reason to discuss the power of Barcelona. The Catalans are playing miles away better than their opponent. They won Club World Cup adding another trophy to their collection. On that roll they can surely defeat Real Betis. Barcelona will play at home and all their leaders are fully fit.
With all that said, I think Real Betis can score in this game. Barcelona are conceding one goal in each game on average while Real Betis have a good number of goals scored against the Catalans. They scored in their last six games vs. Barcelona. So I think that they’ll do it again. But the win will fall to Barca.