Yeah, dollar is so worthless that it gets accepted world wide and you can buy anything with it. If you bought a Bitcoin last year for nearly 1K, you would have lost 40% of it's buying power now.
Get some perspective.
The questions is what time period are you looking at. Do you believe Bitcoin has long term potential? If you have to leave an inheritance in 30-40 years, would you rather bury some dollars today or save equivalent bitcoins?
A dollar in 1980's used to go a lot farther than a dollar today. Bitcoin has built in mechanisms to prevent this from happening. That is the beauty.