Monero
1. No blockchain can be public and forever hidden,
anything they store publicly will eventually be broken
https://cointelegraph.com/news/monero-transactions-history-can-be-revealed-and-exposed-researchSo anyone that uses them should be prepared for it all to be public within 3 years from the date of using it.
3. Bitmain was selling an ASIC capable of mining Monero,
Monero changed the algorithm to disable the ASIC ability to mine monero.
But the fact is , a Monero ASIC was created and bitmain can modify it's original asic to support the changes, the only difference is now they are smart enough not to publicly acknowledge it, they will just keep it quiet and out mine everyone in monero with just a few asics.
PoW is always a winner take all dead end.
* Note: Monero being a failure is not a supply issue because of endless supply generation, but a failure it still will be. *
I used Monero 3 years ago and my transactions are not revealed yet although protocol was way less private built as today. How many more years I will have to wait that my 3 years old transactions will be revealed on your opinion?
No one ever was selling ASIC miner for Monero before they realize mining alghorythm will be changed in few weeks time. This is the only reason why ASIC miners are bad thing. You never know is there is someone secretly mining with more advanced ASIC miner then everyone else.
Monero solved this problem with RandomX. You can buy best ASIC miner in your local computer store. It is called Ryzen. True Satoshi Nakamoto & Nicolas van Saberhagen vision.