There is no point in focusing on BTC/USD equivalence for the long term:
1) You don't know when BTC will reach its peak value
2) You don't know if the USD will be around at that point, and if it is, how much a sandwich would cost
3) If BTC reaches its peak value, no one will care about the USD conversion
I agree with you. What I said has nothing to do with BTC/USD equivalence. The sandwich was just an arbitrary example. Even if USD disappears people will still want a name for smaller denominations of BTC.