Qualified and secure PayPal users can become a Virtual Terminal.
Instant pay, never been hacked, they are the best. Access by Windows 10 and Microsoft Defender.
Regarding blockchains:
Every server in a decentralized system has its own uniquely encrypted copy of the blockchain.
Data quality is maintained by massive database replication and computational trust.
No centralized “official” copy exists and no user is “trusted” more than any other. All of the servers have to “vote” to allow any identical and retroactive changes.
Transactions are added to the block they are building, and then broadcast to the entire network.
Blockchains use various time-stamping schemes, such as proof-of-work, to serialize changes.
Danger:
Growth of a decentralized blockchain is accompanied by the risk of centralization because the computer resources required to process larger amounts of data become more expensive.
Since you seem to understand the “logistics” of it all, I have a silly question...
If in a few years there was a sophisticated hacker(s) who could change say half of the encrypted database network, would that result in a civil war, so to speak, of which database network had the real (true) transactions?
Maybe the Blockchain “founding fathers” have already anticipated this and planned accordingly.