Not a fan of downvoting for contributions that are on topic, in fact I can't downvote on HN and I think I prefer it that way.
But there is a reason why what he posts is just non-sense. Cardano doesn't scale farther than Ethereum or in fact any other blockchain that bets heavily on decentralization. Cardano can do nowadays a theoretical maximum of 6-7 transactions per second [0]. In practice, it's doing around 1 transaction per second because it doesn't see much use [1], which is the true reason why transaction costs are negligible. While Ethereum does 15-20 transactions per second, day in and day out and is working at full capacity [2], which is why Ethereum transactions can be quite costly as the demand is greater than the available blockspace. These are by the way real transactions, not the theoretical maximum I presented for Cardano.
Transaction throughput has nothing to do with the programming language used, it's an intrinsic limitation of the blockchain and is dependent on a bunch of network parameters that you can tweak (block size, block time and transaction size). You can tweak them a bit but if you tweak severely then you pay the cost through decentralization as the compute and network requirements of the node rise quickly, requiring beefier nodes which lead to centralization. A centralized blockchain is pointless, it's like running a SQL database with extra steps. See the recent Solana outage [3].
The programming language thing is just a distraction that has nothing to do with scalability. Ethereum doesn't run Solidity, the Ethereum Virtual Machine (EVM) runs the low-level OPCODES that it has defined [4]. Solidity code is transpiled into lower level languages and converted into the EVM's OPCODES. In fact, there are other programming languages to write Ethereum Smart Contracts like Fe (heavily inspired by Rust) [5] or Vyper (heavily inspired by Python) [6]. In the same way, Cardano doesn't run Haskell or Plutus or Marlowe, it runs the OPCODES defined by its Virtual Machine (IELE). Poor language-design and poor transpiling can lead to some inefficiencies in the performance of the code but in the end the true bottleneck is in the network throughput.
Blockchain scalability is solved via Layer 2s and sharding. Cardano is very far behind Ethereum on this regard considering Ethereum has deployed as of today many different layer 2s [7] while Cardano doesn't have any and you cannot expect to see any for the foreseeable future as they just released smart contracts. Cardano's layer 2 roadmap is also antiquated as it relies on state channels [8], which is a scalability solution that is intrinsically more limited than Rollups. State channels were all the rage a couple of years ago but they have been superseded by rollups as they are far less limited [9].
[0] https://www.reddit.com/r/cardano/comments/prbhp4/cardano_blo...
[1] https://cardanoscan.io/
[2] https://etherscan.io/chart/tx
[3] https://cointelegraph.com/news/solana-attributes-major-outag...
[4] https://ethervm.io/
[5] https://github.com/ethereum/fe
[6] https://vyper.readthedocs.io/en/stable/
[7] https://l2beat.com
[8] https://cardanians-io.medium.com/hydra-cardano-scalability-s...
[9] https://www.reddit.com/r/cardano/comments/pf25jk/comment/hb1...