Safari 26 on iPhone and iPad brings websites closer to app-like experiences....

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

Safari 26 on iPhone and iPad brings websites closer to app-like experiences. When you add a site to your Home Screen, it can now open in a cleaner, full-screen view without browser bars