To answer your question, the USD is back by the US government, which is the reason its inflation is contained, as opposed to the silly currencies of failing economies. What is BTC backed by? It's also highly inflationary since it can't hold its value against speculation.The question you need to ask is what's backing the U.S. dollar? Would you rather own an asset with a finite supply or one where the supply is ever increasing? Look, the only reason why gold is considered a safe haven is because it's a rock in the earth that requires ridiculous resources to extract out of the ground. In other words, there's scarcity of that resource which creates value over time. The same applies to cryptos. You can't just snap your fingers and create a bitcoin. There are real companies with real resources that comprise buildings, servers, networking equipment and other specialized pieces of hardware that are required to mine just a single coin. It's not a game like GTA5. It's real people with real resources doing real work.
We know BTC can't be an everyday currency due to its high transactional cost, cost which it was meant to eliminate in the first place. So what then? A bank to bank transactional method? Sure, but who needs BTC for that? Blockchain is really smart, but what prevents the world's banking system from using that tech without BTC? Every other clown out there is creating ridiculous blockchain currencies that demonstrate the absurdity of the program.
I have yet to find someone who can explain to dummy me what world problem Bitcoin is meant to solve. But I'm all ears!