Safari 26 helps websites feel more like native apps on your iPhone and iPad....

https://victor-wiki.win/index.php/Why_Do_Some_Home_Screen_Website_Icons_Open_in_a_Tab_and_Others_Do_Not%3F

Safari 26 helps websites feel more like native apps on your iPhone and iPad. When you add a site to your Home Screen, it can open in a clean, app-like view without the usual browser bars