Safari 26 helps many websites feel more like apps when you use them on iPhone...

https://bizzmarkblog.com/why-does-my-ipad-web-app-feel-different-from-the-same-site-in-safari-tabs/

Safari 26 helps many websites feel more like apps when you use them on iPhone and iPad. When you add a site to your Home Screen, it can launch without the browser chrome, giving you a cleaner, app-like experience