> New bitcoin from mining is halved every ~4 years, so every four years miners can afford to spend only half as much electricity to mine from that revenue.
Not exactly. Miners are paid out of the sum of block reward and fees multiplied by the market price of BTC. Every ~4 years the contribution of block reward goes down, but that doesn't mean that the price goes down, or that the contribution of fees stays the same.
If it was block reward alone and the "energy problem solved itself" then the blockchain would be completely vulnerable to a 51% attack and it would instantly become worthless.
The expectation is that the contribution of fees will go up as the block reward goes down, although it remains to be seen how much direct fee the market will bear. Currently the actual cost of a BTC transaction is hundreds of dollars - but most of it is socialized via inflation. It is unclear if the market will bear paying hundreds of dollars in transaction costs instead -- and if not, there's no reason the 21M coin limit can't be raised to continue doing exactly what has been happening so far.
> Currently the actual cost of a BTC transaction is hundreds of dollars
I thought... huh, this can't be right. So I did some back of the napkin math. We have about 2500 transactions in a block, a block reward is 6,25 BTC. That comes around a cost of 0.0025 BTC per block, or about 112USD. That's without considering the extra tip from the transaction. So, not really hundreads, but damn' close.
It makes me think increasing the block size really wasn't a bad idea.
> there's no reason the 21M coin limit can't be raised to continue doing exactly what has been happening so far.
Sure, but you'd need a hard fork. Not impossible, but hard to reach the consensus.
Not exactly. Miners are paid out of the sum of block reward and fees multiplied by the market price of BTC. Every ~4 years the contribution of block reward goes down, but that doesn't mean that the price goes down, or that the contribution of fees stays the same.
If it was block reward alone and the "energy problem solved itself" then the blockchain would be completely vulnerable to a 51% attack and it would instantly become worthless.
The expectation is that the contribution of fees will go up as the block reward goes down, although it remains to be seen how much direct fee the market will bear. Currently the actual cost of a BTC transaction is hundreds of dollars - but most of it is socialized via inflation. It is unclear if the market will bear paying hundreds of dollars in transaction costs instead -- and if not, there's no reason the 21M coin limit can't be raised to continue doing exactly what has been happening so far.