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

https://www.bust-bookmark.win/safari-26-on-iphone-and-ipad-helps-websites-act-more-like-apps-by-improving

Safari 26 helps many websites feel more like real apps on your iPhone and iPad. When you add a site to your Home Screen, it can open in a special full-screen mode without the usual browser bars getting in the way