1. Maybe so, but the cost (in time, effort, and money) of swapping currencies is now much smaller. It's not as big of a deal and continues getting easier so I imagine the "one form of money" thing carries less weight than it did in the past even if generally true. Compare swapping digital crypto online VS swapping precious metals/paper money irl. Take for example two businesses except; One accepts Bitcoin-only. The other accepts everything and later swaps what they won't need for awhile to Bitcoin. The second business has a much larger pool of customers and will likely do better, all things equal, even if they prefer Bitcoin.
a. yes, coercive force plays a big role in fiat, but gold is not exactly convenient for frequently settling debts in a global economy either. Paper money was bound to happen in some form instead of settling in gold for every transaction (although crypto changes that now)
b. There is always a lack of information
2. Not sure in what way Bitcoin is a better product unless you are specific about what that is. Better SoV? Maybe, time will see if it continues to hold true. Better MoE/currency? Not so much. Costly to transact, not private, and and weakly fungible. Doesn't seem as if that is going to change soon (if ever) considering the community not liking upgrades and wanting to ossify.
The technical details don't have to be of interest to users for their natural consequences to emerge and affect them. Nothing stop them from saving in Bitcoin and using something else as a currency either.
https://image.nostr.build/ccf181ed168942446d16535fa01942fcb9f471b7b689c9d9f8d12839df0b629c.jpg