Bitcoin is far cheaper and faster to transact with than fiat currency. The only reason Monero is used on the darknet is because of its privacy. That does not offset its shortcomings as a currency. Monero cannot outcompete bitcoin to replace the dollar. Bitcoin will become the standard.
Bitcoin/Monero can't replace the dollar or any national currency for it's citizens. All white markets transactions are controlled by the arbitrary rules of the state (which can artificially offset any gains or inflict burdensome economic costs via taxes/regulations/capital controls that handicap it). Bitcoin won't change that. It's advantage only manifests as between distrustful nation states and black markets.
Did you get my zap comment? Testing if it worked