Liverpool can survived without Mohammed Salah in the squad, they play together and the absence of Salah will not pose any threat.
But Liverpool relies heavily on Muhammad Salah to win in most of their games just as Manchester city rely heavily on Kevin De-bruyne to win most of their games as well, taking Salah out of the picture, the absence will really be felt in the Liverpool's future games; However, it doesn't mean that they can't survive without him, but they have to learn to win with or without his presence in the team.
They are still extremely competitive, but it's always the same with world class players. When they are out for some reason, the team loses some of its world class. It would not be like that if the players weren't world class.
I disagree that these teams rely on Salah to win most of their games. It's in the nature of Salah and how good he is at the game that he scores most of the goals for the team. His contribution is bigger than that of others in terms of goals.
In my opinion Liverpool would still be the favorite for the title in the Europa League even if Salah was out for the rest of the season.