Only Barcelona have a perfect points so far (9 points from 3 matches), no one would be wrong to expect them to become La Liga champions this season, but that's too soon to say, we haven't even go to the first El Clasico of the season yet, so even though Barcelona are currently having a good run, we can't know how they will be after that.
About Barcelona's match against Rayo Vallecano, I thought Olmo played well, it's a shame he didn't play from the start, maybe if he played earlier we could have seen Barcelona's third and fourth goals.
As long as Barcelona are leading by less than three points and until they meet Real Madrid head-to-head, bookmakers will continue to rate them as clear underdogs against Real Madrid (which are still priced at ~1.50 even after dropping points). The fact that they have 9 points is not bad, but you can’t say that they are winning confidently - three minimal victories and in every game they are conceding goals.
Barcelona current superiority certainly makes many Barcelona fans happy with their performance at the start of the season, but they should not forget that La Liga has 38 matches to determine who deserves to be champion and even if Barcelona can able to beat Madrid in the El Classico match that it also not yet can be guarantee that Barcelona deserves to be considered as La Liga champions, currently Barcelona is experiencing a crisis which means they cannot add and improve the quality of their squad if they look at what happened to Dani Olmo previously, so like it or not, Hansi Flick must be able to utilize the current squad and in my opinion their squad is still not capable to compete in tight schedule, although they have a good attack line but we cannot deny that their defense is still very bad at the moment.
So far Barcelona has only faced teams which in my opinion are not enough to test Barcelona mentality and toughness so I think we will see Barcelona true quality when they face teams like Madrid, Atletico and Villareal who do have a solid squad.
They just haven't againts yet ATM or RMA. because only those two teams from Madrid are always competitive to be Barcelona's rivals in the last 10 years. If the barometer is victory against middle and lower teams on the table, then you won't believe that La Liga has 38 matches.
Unless Barcelona wins against Real Madrid and Athletico Madrid, the possibility to be La Liga Champions will be greater because they managed to get points from the 2 teams.
It is true, points are calculated for all matches, how consistent in 38 matches, but at least winning from that two teams is something that can increase team morale.