Lies That Bitcoiners Tell
Executive summary
Cryptocurrency and blockchain promoters are liars. Every cryptocurrency ("crypto") is an absolutely crappy payment system and the most laughable thing that has tried to pass for money -- for several technical, economic, practical, and legal reasons.
Blockchain technology is snake oil: it does not do what it claims to do, and, even if it did, it would not be anything that competent software developers don't know how to implement, much better, without it. That includes the "programmable" blockchains like Eethereum, and all that runs on them: "smart contracts", ICOs, DeFi apps, NFTs, ...
Bitcoin, in particular, is good for only two things: a payment system for criminals, and the biggest ponzi-type investment scam in history.
The lies
Cryptos Allow Sending Money Peer-to-PeerWithout Depending on a Trusted Third Party
False. In any cryptocurrency, every payment between two parties must be validated, confirmed, and recorded by a set of "miners" (or validators) who must be trusted to process it in a certain way, "honest mining".
Computer scientists had tried to design a purely "peer-to-peer" digital payment system, without a trusted third party, since the invention of two-key cryptography. One of the things that such a system had to do was to reject "double spends" -- a party using the same funds to pay two or more parties. For that, all the relevant nodes in the network had to agree on a "ledger" that recorded the user balances and/or the transfers that had been executed. ?? They gave up on Satoshi, the inventor of cryptocurrencies, did ??
Cryptos have no Central Authority
False. The economics of mining (by which we mean the process of validating and confirming transactions) is such that the mining power quicly gets concentrated into a small number of entities or pools. A large miner has many advantages over two smaller independent miners, and concentration makes the network as a whole is more efficient. On the other hand, crypto mining is not subjected to the factors that oppose concentration in other industries, such as transportation costs and local legal and cultural constraints.
This tendency to concentration is independent of whether the network uses proof-of-work (PoW) or proof-of-stake (PoS) or some other method to "secure" the chain. The only obstacle to it all merging into a single pool is the need to avoid the public perception of centralization. But this constraint can be met by having two or more ostensibly independent pools, which in fact have the same owners and managers.
Some cryptos in fact make no secret that they are centralized. IOTA, for example, had to create a central "coordinator", because its complicated "DAG" ledger did not prevent double-spends. Others, like XRP, are completely centralized but hide their centralization behind a complex protocol, featuring volunteer "validators" that, on a closer look, only waste work for nothing.
Centralization in a few miners or pools creates the risk of "attacks" by coalitions of miners.