Well I like when browsing reddit that when I open links they are sandboxed. The in-app browser in that case has an easy button to open to get to my normal safari if I want to.
I’d much rather seen a system-wide “container” implementation a-la-Firefox instead. Safari is pretty good at this but not as good as Firefox. I really want my real-life accounts be segregated from the rest of the internet. Reddit should never be able to know what other sites I use.
Under the implementation in the Reddit app I use (BaconReader), links open in a webview that is an isolated instance of WebKit or whatever the safari engine is called. So already Reddit does not know what other sites I use. Reddit does not have access to the content of my normal safari instance.