Bitcoin is just a distributed ledger which keeps track of which coins are associated with which wallets, where "coin" and "wallet" are nothing more than unique ID numbers. Do you lack confidence that this system actually works, or when you say "confidence in Bitcoin" are you actually referring to some other system built around it?

right, the USD has some institutions and a very large community (i.e. a nation) behind it, and they're huge so its not really an easy comparison with Bitcoin. But Bitcoin is not 'just bitcoin', it also has institutions and a community, they're just much smaller at the moment.