Sevilla are good, but can't really compete with Real Madrid.
Sure. Sevilla is a good team, they can prove it by maintaining his position in 2nd place on the table so far. They actually can compete with Real Madrid and they are doing it now. However, with the quality of their current squad, I am not really optimistic that they can overtake Real Madrid at the top table. Except Sevilla buys some top players in the next transfer window.
As a team, Sevilla has been winning consistently this season. Although there are also those who claim they play consistently poorly, it is less relevant when you're second in the standings. Sevilla should not blow the standing tables when they are in this situation, even if they are to be considered serious contenders. Especially when Real Madrid are at their best. Sevilla's title challenge has already passed the deadline.
Sevilla is the team with the fewest goals conceded, with a huge difference. This represents well the cohesion of the team.