This is true for both iOS and iPadOS -- they way they handle security for links.
Example: I have Youtube installed on the i*device. I click on a Youtube link and it opens in a webview, but doesn't know who I am. I'm logged in via the app, and I'm logged in via Safari, but in the protected webview, it doesn't know. Sometimes it's easy to click on the "Open in App" link, and sometimes it doesn't work at all. If I try to login, then the system sends me to login via Google, which will then send me over to Gmail for MFA validation.
This can't be. It doesn't work like this on macOS. The security model is hell.
This is one of the most mind-boggling parts of Apple’s mobile OS. Why are they allowing apps to jail unrelated parts of the mobile experience? They’re so strict, yet they allow completely unnecessary web views. Photos galleries are another incredibly painful point. Every app thinks they can reinvent the photo picker, for absolutely no reason.
This happens in Android too and it's a little annoying too. If the app is using a certain web view tech (Android has a few) then it enables a frame using your default browser and an option to "Open in (...)" which correctly pops open the YT app. If it's an older web view sometimes it's just impossible - sometimes a share action will work, other times there is a link on the page.
Sometimes I'm logged in (I guess one of those web views got logged into at one point) and then I can watch a few seconds, manually open the app, go into history and restart it proper.
Example: I have Youtube installed on the i*device. I click on a Youtube link and it opens in a webview, but doesn't know who I am. I'm logged in via the app, and I'm logged in via Safari, but in the protected webview, it doesn't know. Sometimes it's easy to click on the "Open in App" link, and sometimes it doesn't work at all. If I try to login, then the system sends me to login via Google, which will then send me over to Gmail for MFA validation.
This can't be. It doesn't work like this on macOS. The security model is hell.