both MVC and Razor pages are the MVC pattern and have the same performance. The difference is the structure of the project.
MVC has folder to define controller actions in, and a separate folder for the razor views. Each controller action build a model and picks a view to render.
Razor pages allows defining the controller actions and the model in the view file itself, so the page actions do not need to select a view (its implicit). All the page actions are the same route, so must differ by request method (get, post, put, delete, etc). Razor pages also has the advantage of building page libraries where the controller code and razor code are bundled.
MVC is considered mature, has only has new features that are shared with razor pages.
Unless you are coming from a MVC background like old MVC or java spring (like myself), you should probably pick razor pages.