Shohei Ohtani and Ronald Acuña Jr. are the rookies of the year and while you can argue the merits of the other candidates, I think the voters made the right selections. In the end, the votes weren't close, with Ohtani getting 25 of the 30 first-place votes and Acuña receiving 27 first-place votes.
Even though Ohtani pitched just 51 2/3 innings, he became the first player since Babe Ruth in 1919 to pitch at least 50 innings and hit at least 15 home runs. Unless you're 100-and-something years old, Ohtani did something none of us have ever seen.