There is a UX benefit I've found, and maybe the app folks felt it as well. Android has a nice universal "back" button which can close an opened tab and return

There is a UX benefit I've found, and maybe the app folks felt it as well. Android has a nice universal "back" button which can close an opened tab and return you the app that spawned it. iOS tried a similar option with a "go back to App" link at the top left, but it doesn't fully close out browser tabs spawned by the app. Safari has gotten smarter about this, with browser "back" buttons closing spawned tabs in many cases, but not all. So, in all those emails where I click to launch a browser to "read more" but see no reason to keep it around, the embedded browser actually plays a maintenance role: no need to get rid of those tabs that were just a funny comment I wanted to see but never need to keep. Yes, the tracking is disappointing, but the UX of not having a zillion tabs open (and in old iOS version, hitting tab limits) makes my life easier.