While one assumes some of these scenes would give Josh Brolin even more time to shine as Thanos, some of the sequences apparently included seeing Thanos as a youth, so we apparently would have seen the character grow up on Titan and learn about all the key moments in his life that led to his decision to find the Infinity Stones by watching him grow up rather than simply watching explain it all to Doctor Strange.
The Russo Brothers have already said that the Blu-Ray for Avengers: Infinity War will likely include a lot of deleted scenes, as they encouraged a lot of improvisation on set, and thus have many different takes of the different scenes in the film.