There is more satoshi than atoms on earth. :)

The system is immutable. No one can steal your coins... In your lifetime.

But the goal of a currency is to be usable. If the currency's supply goes below 1 BTC, this will be a concern because this means that there is 21 bits (zeros) in every BTC price that are wasted. Pure storage space and bandwidth wasted. I don't think asking for a single transaction in a lifetime for the every coins is a concern.