What's hard to understand about a really slow append-only database where you have to set a barrel of crude oil on fire in order to make a commit?

(edit: yes yes, 'proof of stake' blah blah)

DLTs (blockchains) solve the double spending problem in a decentral (trustless) way. Thats "the definition" and what separates it from other similar tech like git, a synced databases or a write-only database. PoW/PoS are just rather stupid ways to implement this its not needed at all. Lookup federated byzantine agreement (FBA) for DLT systems without it.

You know, if you could come up with a better way to implement it, you could become a billionaire. But maybe you already are, everything is possible on HN.

Go to XRPL.org its literally that and it exists since like 2013, It whole goal back then was to make a better bitcoin.

Plenty other projects have adapted the concept or even forked the code. The core team behind this back when it was named opencoin are without a doubt millionaires now and some even billionaires. So you are right but it way way to late now. Not to says that there could not be a even better solutions. But its already several thousand times better if you compare raw metrics like speed/TPS/energy usage etc. an even better solution would likely not make that much of a difference again.

Ripple has issues, iirc. It is not "the" solution yet.

Ripple is a company. The XRPL is fully functional since many years.