Will Cardano take second place on Ethereum?

What will we discuss after Ethereum stops using miners? Miners, miner developers, pools get $13 million every day. This is a big loss for most people. And with the price of Ethereum over $ 4,000, this amount is about 50 million

The so-called big loss that you are talking about will get worse when Ethereum goes PoS algorithm, Ethereum is no more decentralized from that point on and also it will lose its security in some ways, people don't really understand the value of PoW algorithm and what it adds to projects.
Ethereum has over 300,000 validators on the Beacon Chain. 3 mining pools can theoretically execute a 51% attack on POW Ethereum. And 4 mining pools can theoretically implement a 51% attack o Bitcoin. Sounds like the validators might be more decentralized?
Network Validator Count % of Supply Staked
Cardano (ADA) 2,977 69.60% of 33 billion circulating supply
Avalanche (AVAX) 1,199 49.38% of 246 million circulating supply
Ethereum Beacon Chain 309,169 8.2% of 119 million circulating supply