Everyone thinks that Real Sociedad is the better team and will win, but the reality is that Villareal is a team that likes to get a draw, they will play quite well defensively and I think they will do their best to get a draw here as well. A bet that is a draw OR sociedad win could be better than just Sociedad win. I know that the possibility of Villareal getting a draw from this game is slim, but it is not impossible and we should consider the possibility for sure.
I think the best way to go about this game would be picking the draw. This is of course just my guess and I could be wrong and maybe Sociedad will get the win like many expect, but I think it's quite close to being something that would be a draw and boring game.
Villarreal have 4 wins and 1 victory in their last 5 matches. As you emphasized, the draw has become one of their characteristics in the last weeks. On the other hand, Real Sociedad have not had good results in recent weeks. They have only 2 wins in the last 9 weeks. But I'm sure they want to finish in the top 6 of the league. I think they will be the favorites in this match. Or I can consider goal betting options for this match. They are safer options in such matches.