You have a point. But, I believe that USD is somewhat better than Bitcoin because of its stability and wide-spread acceptance within the mainstream world. Other than that, Bitcoin beats the USD by a long shot. The time is yet to come, where Bitcoin will improve its Blockchain network in order to process millions of transactions per second at the lowest cost possible. Once this becomes a reality, then the USD at its physical state will be no more. Then, the USA would need to adapt its national currency into a Blockchain of its own in order to keep its pace alongside Bitcoin and other cryptocurrencies worldwide. It's interesting to see what the outcome will be for the USD within the future, as Blockchain technology has proven to be quite resilient and efficient for worldwide payments.
If we were to compare both the USD and BTC in terms of eco-friendliness, the former seems to be a better choice nowadays. Bitcoin seems to consume a lot of energy, making it harmful for the environment at a larger rate than physical cash. Despite this, it has proven to be the most resilient and censorship-resistant payment system in the world. Which is why, there's a possibility that BTC will become used more than the USD itself over time.
Nonetheless, both currencies (BTC and USD) have their respective advantages/disadvantages. This indicates that neither is better, as depending on the person's needs will be the one to choose. Stability is a key feature of the USD, while for BTC it is censorship resistance. In the future, the USD and BTC will part their separate ways as alternative monetary systems for the world to use. Just my opinion