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

https://bravo-wiki.win/index.php/Safari_26_Web_App_vs_Regular_Bookmark:_What_Is_the_Difference%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