What can you do with Bitcoins but can't do with Dollars?
Long term investment.
In my opinion, this aspect can be done with bitcoin but can not be done with dollars. Well, maybe we can saving our dollars in bank, but it will be stagnan and when theres an inflation our asset value will be damaged with that. But, with bitcoin we can save our assets and can make a lot of profit at the same time.
You can do the same with dollars too. Okay, maybe not with dollars as such but rather US government securities (so-called treasuries) but these are not much different from dollars in terms of liquidity. For example, you can buy treasury inflation-protected securities (aka TIPS) and earn some income over time.
The main difference between bitcoins and dollars is that bitcoins cannot be government-controlled and truly belong to you (as long as you use a personal wallet for storing your private keys, of course) while the dollars you have, both paper and digital, can be confiscated or simply declared no longer valid. And that can happen at any moment.