Sorry, thought my last paragraph covered that. Can any blockchain-backed tech handle the number of transactions per second that current major credit card/payment networks do?

One benchmark is 1,700 tps for VISA. https://phemex.com/blogs/what-is-transactions-per-second-tps

If not, why not? Especially after 10+ years of development and intense VC funding (as is the parent article's point).

Solana’s on the same order of magnitude as Visa. Some people dispute the exact figure, but it’s basically there: https://www.benzinga.com/amp/content/25031541

Next long term target is speed and energy efficiency of a Google search.

Edit: Avalanche says they’re around 4.5k tps: https://support.avax.network/en/articles/5325146-what-is-tra...

Fastpay can pretty much do infinite transactions/s

1,700 tps for VISA is a good benchmark. I recall VISA's technical capability is 10x or 100x that number,

Ethereum 1.0 can handle 30 transactions per second.

Part of the development dubbed "Ethereum 2.0" is focused on scaling the number of transactions via sharding. Each shard will be able to handle 2,400 tps. As more shards are deployed up to 64, Ethereum 2.0 will reach 160,000 tps.

I am interested in learning about how "shard chains" work.

I'm concerned after reading https://ethereum.org/en/eth2/shard-chains/ that sharding is aimed at letting individual dApps roll up transactions -- i.e. the individual app would be the effective shard key -- and thus that would introduce some notion of centralization into the system.

I imagine there are some good podcasts or articles discussing sharing in greater depth. I'm interested as well if anyone has suggestions!