Once you 'see all money in circulation' linking the circulation to the users isn't hard. Or by 'all money' you mean just one number for the total supply?
Cryptocurrencies don't necessarily need to "see all money in circulation" ie: able to go count it all up wherever whenever, or to count or know or decide or consensus on one single supply number stored somewhere. They can do those things, but it's not the only way. They can also rely on software in operation proofs. If SW prints one widget per day, and cannot print less or more, then 1000 days out there are exactly 1000 widgets, regardless if anyone can see/count them or not. Of course SW operations can be hard to prove in formal analysis. And Zcash-ZEC and other coins that did not do due formality got bit with that bugs and had to do turnstiles and other tricks to restore confidence. But the fundamentals of proven formal analysis can provide alternatives to first generation "must see track and spy it all" thoughts. Nor do cryptos need to see who is spending what, on what, where, when, from, to, amount, etc. The dawn of homomorphic / zkp crypto tech should give rise to fun future of formality and privacy constructs therein. They could also play a role in eliminating the stupid waste of growth per tx "blockchains", instead moving to per UTXO key. Bitcoin-BTC is not "leading" because it was some innately good coin, it's leading because it was first, and it still kinda works. It has massive privacy issues and refuses to do anything about them. People are taking coin privacy much more seriously now. And it has growing centralization risks due to limited scaling and ASIC abuse. Any fully distributed featureless coin that does privacy, does away with per tx growth, has maybe 100 to 1000 native tps rate, works with a DEX API... is going to be a strong contender.