Bitcoin does not need the dollar, right now the most powerful currency is the dollar and that is why every currency is compared to it, when bitcoin takes that spot then every currency will be compared to bitcoin instead.
...Nevertheless, while Bitcoin may be far from replacing the dollar soon, it could stand alongside it, that can be used as an alternative payment system in the time of need. Just my thoughts
Definitely agree on this one. Transitions like this go slowly. And governments won't be too fond about having zero control on their currencies. So if it would actually replace fiat currency, my guess is that we could easily wait 50 years. But more likely it will complement fiat currency .