If EvilCorp has 20% of the network hashrate then sending a payment to anyone not using their centralized servers will take 50 FRAGGIN minutes for first conifrmation due to witholding the the tx from the other 80% of miners.
They don't have to withhold those. I said it can be insideous attack, where they slowly starve the network over time and build theirs. They are stealing (siphoning) resources and building their mass. Eventually they reach critical mass.
Yeah I see that service being "super popular". Even if people don't care about the network security they certainly don't want massively delayed txs just so evilcorp can rule the blockchain.
Of course the cartel wouldn't withhold transactions sent to parties who are not in their cartel.
But I think you fail to appreciate even how small businesses use Amazon to sell through.
Cartelization is the natural outcome of commerce and we see it happening before our eyes now.