The only reason if there is any, for digital dollar to be a threat to bitcoin will be it having characteristics (blockchain) features as that of bitcoin. Apart from that, I don't see it as a threat to bitcoin. The government will still control and own the digital dollar, which can be regulated and reversed, unlike bitcoin. The dollar is a worldwide currency that is used for various exchange purposes and cross-border payments, thus its digitization will benefit the government but will never pose a threat to bitcoin.
Indeed, although the dollar as a worldwide currency, this will not give a big impact on Bitcoin. However, as we know that this day is a digital world day. I mean that many more systems are operated digitally, yes, of course, the existence of a digital dollar cannot be ignored. The development of this digital era is very rapid, so it is possible that the digital dollar will also continue to grow rapidly. However, this again will not have much of an effect on Bitcoin. Because we ourselves know the function of each. The dollar, still centralized, is controlled by the government and the world bank. Whereas Bitcoin is not. This is what remains the attraction to Bitcoin. And what's more, Bitcoin is not only a means of payment but also a valuable investment tool.