Earlier quoted context omitted.
And also Aztec Network, and Tornado Cash, and Zcash, and soon Starkware, and... I'm surprised so many people on Hacker News apparently still believe that you can "see all transactions" on every blockchain. It really only takes some surface level research to find working, production blockchains/cryptocurrencies that use one of several types of cryptography to hide that data, plus if you're using a pseudonymous blockch…
Well, you have to see all transactions, in order to know the current balances on every wallet, in order to prevent double spending. This is, in fact, the whole principle on which blockchains operate.
Monero uses a system that at a high level is referred to as Ring Signatures (it's not too complicated but it's more than I want to get into at the moment). Zcash and other networks use zero knowledge non-interactive proofs to prove consistency/correctness.
The major drawback of privacy preserving chains is that the transactions are expensive to compute due to all the maths that goes into maintaining that consistency without publicly leaking information. This isn't prohibitive for a desktop but a mobile phone will likely take a few minutes to build and send a transaction in the current environment (can be improved by HW acceleration or general HW improvements).