I think in this case, willingness and ability end up in the same place.

Bitcoin fees are paid from the inputs, so either you have enough or you don't.

If it's not economically worth it to you to make the transaction (and pay the fees) it's the same as not having enough to pay the fees.

As far as the fiat to bitcoin to shitcoin to fiat cycle, no one can mint bitcoin, so shitcoins (including fiat) valued in bitcoin will continue to decrease. As long as they have to buy bitcoin at some point in the cycle (which they do in order to pay fees) they will run out of money unless there is a real economic use for what they are doing.