yeah, a very boring match, both of them played just to play, not to win, players were lacking motivation,
You know it, so it is normal if there is nothing interesting in that match.
Real Madrid already won the La Liga title, while Betis can't improve their position. Surely both have no motivation to win, they only played without any purpose in that match. Because of that reason, both teams won't play all out that may spend all energy, especially Real Madrid that needs to keep their fitness to play in UCL final.
But luck for Real Madrid because they can keep their touch of the game to stay at their best. This can be used for the Real Madrid camp before they appear all out in the Champions League final which will definitely drain their energy and concentration. This is like a warm-up event for Real Madrid for the final match later.