Safari 26 brings a smoother, app-like feel to many websites on iPhone and iPad....

https://post-wiki.win/index.php/Why_Do_Animated_Web_Games_Stutter_on_Some_Phones_but_Not_Others%3F

Safari 26 brings a smoother, app-like feel to many websites on iPhone and iPad. When you add a site to your Home Screen, it now opens without the browser’s usual bars and controls—just like a real app