> But you would be a fool if you claimed it wasn't wasteful just because the product (light) is so valuable.

you're missing the fact that bitcoin difficulty adjusts. ultimately bitcoin mining is an activity that converts energy into blockchain security. market establishes the required level of security by assigning value to bitcoin. if you replace bitcoin algorithm to anything more "efficient" - it will simply mean that miners will churn through more iterations of hashing but amount of energy consumed will not change because it's dictated by the market.

> Bitcoin mining is wasteful, it literally produces waste

wrong. bitcoin mining produces blockchain security. waste (and more correctly - energy consumption) is just the mechanism.

I'm not missing any facts, and you're just ignoring my argument. What's your game?

Your argument is invalid exactly because you’re missing the fact that difficulty adjusts. Lightbulb produces light by consuming energy just like bitcoin miner produces hashes by consuming energy, but hashes aren’t the product we’re after, the valid block signature is. If difficulty was static we could be arguing that there is more efficient way to convert energy into valid blocks, but since difficulty adjusts - energy efficiency doesn’t matter, market says X amount of energy should be spent and so it will be spent no matter which hashing algorithm or how efficient the hardware is.

Lightbulbs produce light and waste. Bitcoin produces block security and waste. It varies the amount of waste it produces with the value that's being secured, and in practice that just means it produces more waste when there's more value. That the amount is adjusted according to market demand does not matter, because the market is not interested in minimizing waste, it is interested in maximizing value.

My metaphor was intended to show you that with innovation we might find better alternatives that have similar or better value, at lower cost. It could be that we can get the same or similar security Bitcoin offers, but without the cost of the enormous energy expenditure.

> Lightbulbs produce light and waste. Bitcoin produces block security and waste

all consumption of energy produces waste, the question with lightbulbs is whether we can get more light with less energy and certainly from 100 years ago there was lots of progress.

the same question simply doesn't apply to PoW currency, because energy expenditure is the goal since it directly converts into security. you can't ask for more security with less energy if security is defined in terms of energy. and that's exactly the case with bitcoin.

if you want your metaphor to work - imagine a lightbulb that has a dimmable enclosure and it automatically dims proportionally to how many lumen is emitted so that luminosity of the whole device is constant. no matter how much energy you throw at it or how efficient you make the lightbulb - the apparent outcome is the same, therefore there must be something else this process gives you to justify expending this or that amount of energy.