Earlier quoted context omitted.
Then devs should research and develop PoW which is more efficient and takes less energy and come up with solution that does additional useful work on top of verifying transactions.
'PoW which takes less energy' is an oxymoron. The whole point is to demonstrate cryptographically a certain amount of effort (combination of energy and efficiency of hardware implementing a deliberatly inefficient function) has taken place. The network adjusts the difficulty dynamically depending on the amount of effort being put in (basically the rewards are fixed: miners simply compete for a bigger slice of the pie…
You can rewrite difficulty formula and make it easier to mine and therefore decrease energy consumption. Bitcoin's protocol is set in stone but if some dev likes to play with protocol like Vitalik he or she can do it. It would shift market and coin price downwards but if energy consumption is really a problem it is tax you have to pay.
>There's no particular reason bitcoin's rewards are either not overkill or sufficient to secure the network against an attacker.
Satoshi introduced blockchain checkpoint which basically enforces consensus.
"The security safeguard makes it so even if someone does have more than 50% of the network's CPU power, they can't try to go back and redo the block chain" [1]
This is centralized decision but it is better than changing protocol completely like Vitalik did (going from PoW to PoS).
>because the currency has built-in adjustments which can be made by the foundation, in theory it can adjust the block reward dynamically to the right amount, though there's both political issues in terms of appeasing the miners when you cut their profit and technical issues in actually working out what is good enough.
So centralized foundation controls decentralized network? And what is right amount?
>But at a certain point it's more profitable to attack the system than secure it, so it's a difficult balancing act.
How come? When all coins are mined miners will switch to transaction fees and they will compete for transaction fees. If you want faster confirmation time you will pay higher transaction fee for your transaction meaning miners earning more, you can do this now as well.
>Likewise 'doing additional useful work' is not something you can actually do in a trustless manner like with proof of work
It doesn't have to be additional useful work it can be in the core design of the proof of work.
In 2013 there was a coin called Primecoin which "computed chains of prime numbers (Cunningham and bi-twin chains), the results of which were published on its blockchain's public ledger, available for use by scientists, mathematicians, and anyone else."[2]
"Use of a proof-of-work system to calculate chains of prime numbers was an innovation that produced useful results while also meeting the criteria for a proof-of-work system: it involved a calculation that was difficult to perform but easy to verify, and the difficulty was adjustable."
It was first coin which had a proof of work with a practical use.
It is still early days but this is the most recent paper I found about this matter: https://eprint.iacr.org/2017/203.pdf
[1] https://bitcointalk.org/index.php?topic=437.msg3807#msg3807