In hindsight it makes a lot of sense. The cost of a transaction for Bitcoin is always going to be higher than just updating a value in Visa’s database. Visa may have some increased costs due to consumer protections, but consumers are pretty clearly willing to shoulder the cost.

Weren't Ethereum and Cardano supposed to solve some of those problems?

I have never heard of Cardano and Ethereum seemed to market itself as a way to run the internet and government inside of blockchain while the reality was it was never used for anything but speculative investment.

Cryptos have basically burned the idea and the general public will probably not care of any future solution since all of the previous ones were scams or not very useful.

These cryptos all promise the world and deliver nothing.

Ethereum is producing insane value.

For example, Uniswap is a decentralized exchange living on top of Ethereum that frequently has volume higher than Coinbase. A couple years ago that was the "end vision". Now it's an everyday reality.

Loans, mutual fund like assets, lending etc. The ecosystem is booming.

Ethereum is absolutely fulfilling it's mission.

https://defipulse.com

If everyone else is getting the same dozen daily scam emails related to Ethereum that I am, I'd have to assume that it has irreparably harmed the currency's reputation.