Safari 26 on iPhone and iPad brings websites closer to apps by improving the...

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 apps by improving the Home Screen experience. When you add a site to your Home Screen, it now opens using the new 'Open as Web App' mode