Replacement doesn't imply a reuse of a specific location. Taking an ad out your browser and placing a different ad on your desktop is still replacement. Do you really not understand that advertising isn't about space in physical world, but about space in your mind? What brave does is absolutely replacement. They replace a bit of light that was emanating from one part of your device's screen to invade your attention to make some other party money with a bit of light that emanates from a different part of your device's screen to invade your attention to make them money. How in the world is that not "replacement"?