A lot of them, or at least the big budget films, having been following the Marvel formant...and honestly MOST Marvel posters are meh at best.
The OG Sonic while iconic for what it started, as a game seems kinda meh and bland and when Sonic 2 came out it really built the foundation for what the series would become. People often forget that you cant do the Spin Dash in the OG game. The first game built the foundation...even if it was kinda simple and vanilla and then the sequel aim for the stars (figuratively and literally)
I feel the movies are following the same path...in a way. The first movie was simple. It established who Sonic is as a character. His relationship with Robotnik, Tom and Maddie. And now with the sequel they can go crazy with all the game stuff.