Sonic Mania was a very special moment for the Sonic franchise. After years of releases that were pegged as good-to-mediocre, Sonic Mania became a major hit with both critics and gamers alike. It was a return to form for Sonic, and it absolutely paid off.
In an interview with LadBible, Sonic Team's Takashi Iizuka mentions how important Sonic Mania has been for the franchise in general.
"...post-Mania, I feel the character, and the games, have really turned a corner, towards where we want it all to go."