Looking at their H2H in La Liga, Barcelona have won more matches both home and away and with the current positive conditions I doubt a draw will happen I am more confident that Hansi Flick's squad will get 3 points besides that because Real Sociedad are not in good form this season in 12 matches they have only scored 10 goals which shows their attack line is not impressive.
I am questioning the odds given by the bookies maybe they consider because the match was held at Real Sociedad's home ground but the odds are quite profitable and worth betting on.
Statistically and team quality of course Barcelona on paper is more favoured than sociedad in the match later, as you said so far the performance and consistency possessed by Hansi Flick squad is more promising for victory over Sociedad because of their current advantages both in defence and attack, with a sharp attack line and solid defence, Barcelona seems to be in a more favourit position in the match, unlike sociedad, although playing at home, but so far they are in bad condition and not found their best performance this season
Without looking at the statistics, I think Barcelona will still be very convincing in winning. This season, the club in La Liga that is most difficult to lose is Barcelona and Real Sociedad position as the host team is not a reason to be able to dominate the game. So 3 points for Bacelona without having to worry and it is certain that La Liga has no obstacles to lifting the trophy.