There is no way that a deflationary asset could become the world currency because of the economics behind it. Say you were to take out a mortgage in the future for 1 BTC at a price of $250,000 USD. You have to pay the bank back 1.1 BTC (for simplicity's sake) over 30 years. As more and more BTC is lost due to people losing their seeds, the price of BTC increases. Well, throughout your mortgage, the average price of BTC was $500,000 USD and you paid $550,000 for your house.
This is a really simple way of saying consumers may postpone purchases in the hopes of getting better deals in the future, leading to decreased demand for goods and services. This can result in lower production and job losses, further reducing demand and creating a self-reinforcing cycle and increase the real value of debt.
Yes, it can be good that you have 1 BTC now, but it won't work for a global economy and for newborns.