In season 7 the world forcefully reminds us about itself - here are we in England, here we are in Berlin, Istanbul, etc - and here is the whole world comes crushing to a small house on Revello drive, giving us a slightly claustrophobic feeling. This centripetal motion ends up with the big explosion, giving Buffy the whole world with that wonderful last shot.

That's a really great observation, one that never occurred to me before.

that claustrophobic feeling was due to shrinking production values and not higher creative considerations

Pffft. What a useless thing to say. Obviously it was someone who didn't see any value in the last few seasons, which is her loss.