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

https://mag-wiki.win/index.php/How_Do_You_Keep_a_Web_App_Fast_and_Responsive_on_Mobile_Safari%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 in a clean, distraction-free window without browser bars