What I meant is that this feature is okay for your personal use, but it's not suitable for all uses. For example, if I want to play Beat Saber in my room with the boundary but after want to play Beat Saver in the living room without boundary, if the boundary settings is set per applications, I will have to edit my profile to set it ON or OFF depending on my use case. But if this feature is just set globally, you don't need to edit your each games profiles, but do it globally.
And when I spoke about children or friends, if you give them your Quest, you will not want to re enable boundary for all the games they want to use by editing each game.
Sorry I'm french, not always easy to explain that in english