Indeed, the point difference isn't much among those teams. Only the top two teams, Real Madrid and Sevilla staying ahead. But the leaderboard race is also competitive between them. The point difference is 5, but Sevilla has played 1 match less than Real Madrid. The position will change after each weekly round and there will be notable changes in the leaderboard within next three to four rounds. 11th rank team Espanyol is also in that dense group.
Yes, you are right, Sevilla is the only one holding on to Real Madrid with dignity. But now the gap between the teams is 5 points, and the fact that Sevilla played 1 game less and can get closer to Real is only a theoretical possibility. Because this game still needs to be won. La Liga is a rather unpredictable championship and they can lose points in any match, so don't jump to conclusions.
The distance that is getting smaller is certainly a threat to Madrid. They had to keep accumulating more points if they didn't want to be overtaken. Sevilla started to increase the tempo of their matches and tried their best so that the points difference was not too big with Real Madrid. The rest now only need 5 points. Maybe in the next game, Sevilla will try to be more aggressive. Like being given fresh space by Real Madrid, most of whom feel safe because they only have points, without realizing that behind them there is Sevilla who are motivated to minimize the gap.