A long time ago: 1 bitcoin for 1/10/100/1000 dollar was too IMPOSSIBLE, so said people..
In order for the value of 100 satoshis to equal the purchasing power of $1 USD today, the price of a single bitcoin would have to reach $1 million. That means that Bitcoin itself would need to have a market cap of $21 trillion. Such a large market cap would only be possible if Bitcoin replaced all fiat currencies everywhere in the world. That means there would be no USD, no CNY, no JPY, no GBP, no EUR, etc. This is the best case scenario for Bitcoin and it's also one that Hal Finney even considered and hypothesized about back in 2009 during his conversations with Satoshi:
So the possibility of generating coins today with a few cents of compute time may be quite a good bet, with a payoff of something like 100 million to 1! Even if the odds of Bitcoin succeeding to this degree are slim, are they really 100 million to one against? Something to think about...
However, it's also far from straightforward. It's easy to go from a $1,000 market cap to a $1 million one or even a $1 million market cap to a $1 billion one but it's much, much harder to go from a $1 billion market cap to a $1 trillion one despite the increase in magnitude being the same.
How many businesses with >1 billion dollar market caps do you know of? I'm sure you can think of many. Now ask yourself the same question but with >1 trillion dollar market caps instead. If Bitcoin does ever end up overtaking all national fiat currencies, then we will eventually see coins worth $1 million. But you can't really compare the step up from $1 to $1,000 with the step up from $1,000 to $1 million. They're two completely different things.