So if the phone gets a security update for this at the OS level, should we theoretically be safe to use apps with any sort of browser functionality? Like some apps that don't update, or are no longer being maintained, etc

I just don’t like the idea of having 500 accounts after it’s all said and done, especially if most of them wind up being unused… unless I’m fundamentally doing something wrong by creating a new account on every instance I want to use?