There is no personally identifiable information stored in the public ledger. Just addresses, scripts, and Bitcoin amounts. If someone that knows you (like an employer or a Bitcoin exchange) sends you Bitcoin, they will know addresses that you claimed were yours. As soon as the Bitcoin moves from those addresses to another address then the provable link to you is broken.
All the chain analysis you have heard of is based on likely patterns and typical behavior of address use in common Bitcoin wallet software. New signature and script schemes have been added to Bitcoin in the past several years that disrupt those patterns and make it even harder to find connections between addresses.
"Addresses" are personally identifiable information if you're associated with one, or if you use an exchange, which you'd want to because most people providing goods and services (and also your local tax authority) want the local currency.
If you're claiming these upgrades made Bitcoin anonymous in 2021, that's obviously not true, since multiple people who stole billions of dollars of bitcoins from exchanges have been caught with chain analysis since then.
Ok, first off, let's take a step back here. We are discussing a solution to this unbanking problem, but you and I have gotten off into the weeds a little about hiding actual criminal activity. Bitcoin is not 100% private, but it did take 10 years and this guy inviting the police into his home where they found his physical bitcoin wallets in order for him to get caught. That only supports the point I'm making that Bitcoin anonymity, though not perfect, is still pretty damn good. Good enough to fix this current unbanking problem.
Bitcoin is not magical and perfect, trade-offs have to be made in any endeavor. I personally think the ones Bitcoin has made are good ones. Maybe you still disagree.
Nah, the real issue (which it shares with every other crypto project) is that it invented a kind of decentralized network that doesn't get better with more nodes but still manages to use more energy.
Of course, all later ones are funnier. People think Ethereum is a distributed computer! But the whole network runs at the speed of a single node.
If you want to trade numbers with people over the internet, I recommend using Google Sheets. Maybe ban people if they edit it wrong.
All the chain analysis you have heard of is based on likely patterns and typical behavior of address use in common Bitcoin wallet software. New signature and script schemes have been added to Bitcoin in the past several years that disrupt those patterns and make it even harder to find connections between addresses.
Further reading:
https://river.com/learn/bitcoin-privacy-and-anonymity/
https://river.com/learn/what-is-taproot/