Eth developer here. Re: sanctions, the problem with any non-privacy coin is chain analysis lets you blacklist wallets that have interacted with North Korean wallets or whatever. On Ethereum we saw a mass blacklisting of addresses that had received money from Tornado, commonly used to launder exit proceeds. (Amusingly enough, this was also used to grief big wallets by sending them some money through Tornado.)
So as long as you depend on external companies that are subject to sanctions, you will have degraded utility for dirty wallets/coins. You'll have a two tiered system: wallets/coins that have access to US banking off-ramps and ones that don't. As Tornado showed, mixers don't really solve this because a motivated enough entity just blocks everything that uses the mixer.
The buyer of last resort argument is interesting, but I think this just "wasting" power in a different way. Bitcoin transaction fees buy it from the power plants, and then miners waste it. So Bitcoin subsidizes power plants. Why not just have the state subsidize power plants? You can be selective so that you're not accidently subsidizing coal, and instead of wasting the power you can put it into inefficient-but-not-0%-efficient energy storage. I know this is handwavey and not something the current US government would do, but so is creation of huge green power sources that need a buyer of last resort.
Proof of stake is just okay, privacy coins are great for doing crimes, credit card processors are godawful, but my experience with cryptocurrency has mostly just been new implementations of old finance stuff. Not a lot useful to regular people and it's been years.
Eth developer here. Re: sanctions, the problem with any non-privacy coin is chain analysis lets you blacklist wallets that have interacted with North Korean wallets or whatever. On Ethereum we saw a mass blacklisting of addresses that had received money from Tornado, commonly used to launder exit proceeds. (Amusingly enough, this was also used to grief big wallets by sending them some money through Tornado.)
So as long as you depend on external companies that are subject to sanctions, you will have degraded utility for dirty wallets/coins. You'll have a two tiered system: wallets/coins that have access to US banking off-ramps and ones that don't. As Tornado showed, mixers don't really solve this because a motivated enough entity just blocks everything that uses the mixer.
The buyer of last resort argument is interesting, but I think this just "wasting" power in a different way. Bitcoin transaction fees buy it from the power plants, and then miners waste it. So Bitcoin subsidizes power plants. Why not just have the state subsidize power plants? You can be selective so that you're not accidently subsidizing coal, and instead of wasting the power you can put it into inefficient-but-not-0%-efficient energy storage. I know this is handwavey and not something the current US government would do, but so is creation of huge green power sources that need a buyer of last resort.
Proof of stake is just okay, privacy coins are great for doing crimes, credit card processors are godawful, but my experience with cryptocurrency has mostly just been new implementations of old finance stuff. Not a lot useful to regular people and it's been years.