Some people feel strongly this security is worth it. Some feel strongly that it isn’t (but one suspects their objection is really to the lack of central control)
In that light, and given the ludicrous power estimates that blockchains use, are we not morally obligated to kill all the blockchain projects if these estimates are in the right ballpark?
But, you are right, even that enormous inefficiency is peanuts compared to the Proof of Waste, which ramps it up to unimaginable proportions. (A single BTC transaction uses up as much electricity as a 2 person household in Germany in a year, and produces 2 iPhones worth of electronic waste.)
(sorry i intended this as a reply to a different comment, not yours, not sure how i did that!)
This looks to be the case now, with block reward being dominated by the block subsidy. But by design, the latter reduces exponentially over time, so that within a few decades, the security will have to come predominantly from transaction fees.
If you have a solution for this that does not require trusting anyone, I'm sure that people would love to hear it.
And the fact that you've mentioned one cryptocurrency to fix the transaction rate issue, and another to fix the blockchain size issue, but not one to fix both issues at the same time, has not escaped me.
And speaking of moving the goalposts... You recommended Sui as a blockchain with "basically unlimited transactions per second", and then recommended Mina when I commented about chain sizes. It sure seems like you have a mutually-exclusive blockchain for each set of goalposts to me.
Instead of huge transaction chains to get to the balance people use snapshots where they basically sum up everything in the past to a give point in time and add new transaction from there on.
More "modern" systems like the XRPL or ETH directly use accounts with balances. If you have the last state so all accounts and all balances you can move (subtract from one and add to the other) you dont have to sum past transaction to know if someone actually has a balance to move. You can also easily sum all balances which must give the total (if the supply is fixed).
>"If you have a solution for this that does not require trusting anyone...."
You do not need to trust anyone you need to trust EVERYONE at one point in time exactly when you want to join and use the system. If you decide to use for example the XRPL today maybe even run a node and validate transaction yourself, then at the time "now()" the last state that everyone else agrees on that is what you need to "trust" or rather accept.
You need to accept that to this date the people who ran it before you didn't never collude to "fix" or manipulate the ledger state of the past. If you think they colluded in the past and the current state is not how it should be then the system is useless to you. It doesn't matter if you can point to the exact event in some historical data. And you dont need the historical data to know such an event happen because it obviously would be hugely controversial and well documented outside of the transaction history (probably would result in a fork etc. so you could pick the chain you agree on).
If you are worried about a mistake in the past that no one even noticed then that is not a problem since by definition the code everyone runs is the rules. A bug is a bug in the rules and if everyone agrees on the current state it doesn't matter that something went wrong somewhere in the past, its only important that the current state is agreed on. If you assume the past is immutable then a past bug has no effect on the future function of the system (Exception ofc is when the past was changed then you need to assume that people collude again to do it again).
People think the past is immutable if we have it recorded but actual it is immutable if there is agreement on the current states finality.
Think of the whole system like a closed room with people who together hold a fix number of coins. Once everyone knows the balance of everyone and there is no dispute on the balances everyone can transact with everyone. There is zero need to know the past transactions that took place. If someone has 5 coins he can give you 3 and everyone sees that he now has 2 and you 3 more. If a new person enters the room he must have zero coins else the total increased. He can then instantly accept coins from anyone once he know the current undisputed balances of everyone. Again he does not need to know from whom you got your coins just that everyone agrees that you own them.
As for layer 2's this could partly be the solution to some high costs. But risks sacrificing decentralization.
1) a pure PoS system starts with the creators holding all supply and can keep an arbitrary portion for themselves while selling the rest as they please
2) the truth in PoS is subjective (nodes need to rely on other nodes to determine what is the current state of the system).
A) in PoW you
A1) either put all your resources (hash power) behind one chain, and get the block, thus the mining reward, with probability equal to your proportion of the total hash power (as before) assuming that chain ends up the longest chain (so you have a strong incentive to pick the "correct" one), or
A2) distribute your hash power between the two competing chains, but then each of them only gets half the hash power, and you reduce your probability of getting the mining reward to half, thus halving your expected reward.
At any rate, as soon as one of the chains is ahead, there is a very strong incentive to fall in line with the LCR (longest chain rule) and place all your bets on the putative winner, rather than diluting your expensive hash power.
B) In PoS, you can just continue staking on both competing chains, and whichever wins, you got get your mining reward (as usual, with probability equal to your proportion of the total stake). No incentive to settle on a winner early ("nothing at stake"), so just keep your options open by supporting both chains, and thus no incentive to congeal on a winner quickly.
Yes, and avoiding the trusted party makes it more inefficient by a factor of around 100,000,000 (-ish), if you consider that BTC uses around 23 GW and can do no more (5 transactions a second) than a single trusted PC could do.
What are use cases were you actually need this and the high cost is worth it?