I would completely disagree with calling Severance "the first bonafide hit for Apple TV+".
Ted Lasso was nominated for 20 Primetime Emmys in its premiere season (2020), more than any other freshman series in history. The show won 7 Primetime Emmys including Jason Sudeikis's for Outstanding Lead Actor in a Comedy Series. This year (2022), it was nominated for 20 Primetime Emmys again. It's the most-watched television series on that streaming platform, the first season premiere episode was Apple TV+'s most watched premiere, and the second season of the show increased its viewership by six times over season one.
The Morning Show, now in its third season, was nominated for five Primetime Emmys in its first season (2020), with Billy Crudup winning for Outstanding Supporting Actor in a Drama Series.
Not to mention For All Mankind, SEE, Dickinson, Mythic Quest, WeCrashed, Central Park...