I agree with you that Barcelona had a high chance of losing this match but they are lucky that they could go home with a point. You can't predict the next matches based on one match they played badly in this match maybe they will do better in the next matches and it is almost certain that they will play more better in the next matches.
Based on some podcasts that I've listened to, it seems like some pundits believe in the narrative that Flick's second season is usually not good for various reasons. One of the pundits claimed that Barcelona's high-line/offside trap is a good thing if other clubs can't figure it out, but once they solve that issue, Barca can concede a lot of attacks. It doesn't help that some players got injury, or the pitch condition isn't good, and so on. Let's see if Barca can improve and find their best gameplan asap.