BTC is not for for real life use now, as it'sole purpose was when the algorithm was being designed.

It has become more of an investment option and this is how people have find it's relevancy and this is how it would be considered. Once 21 million BTC are mined, it would be like an asset and you need to pay additional fee to buy and sale BTC, as there would be no BTC for miners to validate the transaction.

So, the problem would remain the same for which the BTC was developed.