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

https://wiki-view.win/index.php/What_Should_I_Tell_Users_Who_Ask_for_an_App_When_the_Site_Already_Does_Everything%3F

Safari 26 brings a smoother, more app-like feel to websites on iPhone and iPad. When you add a site to your Home Screen, it now launches more like a native app without the usual browser bars cluttering the screen