I mean, he makes a lot of sacrifices, but the movie shows how they aren't "real" like Gamora screaming about how it isn't real love but abusive, awful, manipulative love. He's awful in that he feels bad about dropping Gamora, but tortures Nebula without a second thought. He's meant to be a manipulative ******* and not sympathized with. The movie showcases his "sacrifice" as a major part not to let us feel bad for him, but to highlight why the heroes lost: they couldn't make the sacrifices like Thanos could. Loki couldn't let Thor die, Gamora couldn't let Nebula get tortured for all eternity, and the Avengers were refusing to kill Vision until the last second.
At least, that's how I interpreted the movie's intent. Maybe it's all meant to be interpreted a different way, idk