Yes, this could have been done with CGI, but that seems unlikely. As others mentioned, doing this level of CGI destruction is super expensive, and destroying stuff is pretty cheap.
But there's also the bigger factor that, if Apple didn't destroy a bunch of stuff, why haven't they said so? It seems to me that if this ad was entirely CGI, Apple would admit that to minimize the backlash.
Therefore, unless Apple says something (or someone does some very convincing analysis), I'm inclined to believe this ad was done primarily with practical effects. That's just where the evidence is pointing right now.
But there's also the bigger factor that, if Apple didn't destroy a bunch of stuff, why haven't they said so? It seems to me that if this ad was entirely CGI, Apple would admit that to minimize the backlash.
Therefore, unless Apple says something (or someone does some very convincing analysis), I'm inclined to believe this ad was done primarily with practical effects. That's just where the evidence is pointing right now.