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

https://sierra-wiki.win/index.php/How_Do_Web_Apps_Handle_Authentication_and_Accounts_Without_a_Native_App%3F

Safari 26 makes websites on your iPhone and iPad feel more like native apps. When you add a site to your Home Screen, it now launches in a clean window without browser bars, just like a regular app