Solana has made many sacrifices to decentralization and basically requires a super computer to operate a validator. As a result the chain is so centralized it actually went offline for a day which is unacceptable.
Cardano is just a hot mess. They spent years in research to "fo things right from the get go" and since their launch have had a ton of issues and realized why ethereum made the decisions they've made.
Polkadot is pretty much following ethereum's rollup design but their downside is it's pretty much a vc chain like the others.
Nobody would miss these chains if they disappeared, just like nobody misses the previous wave of "eth killers" (eos, neo, tezos, lisk, etc). They come in with a huge marketing budget to mislead the likes knowledgeable mainstream, but the builders see through all that nonsense and as Palmer says, "developers, developers, developers".