The 'costs' of proof of work are indeed high though. The amount of energy consumed for one bitcoin transaction to happen is astounding. My point above is that there are numerous alternatives (which in my opinion are poised to topple bitcoin), which don't have these costs.
I disagree with 'no benefit to the species' (even bitcoin has many benefits). But the costs of bitcoin are also high, and the benefits can come without those costs.
The government, tax, justice systems and regulatory bodies are made out of people, you can't fool them with some "haha it's not USD" technicality like a sovereign citizen. It's all the same at the end except for a bunch of wasted energy.
Even though there are a fair share of 'sovereign citizens' among cryptocurrency types, there are many who just see the potential for integration with existing infrastructure. Personally I'm more socialist-leaning, and want governments to embrace technology that will also empower them to provide sweeping social benefits for their citizens in a transparent way.
At the same time, the leading crypto platforms enable an amount of transparency that isn't possible with traditional financial institutions.
The wasted energy argument has already been addressed, and is specific to proof of work platforms which are the minority of the top 50. After the ETH2 transition is complete, it's likely proof of stake crypto will have a larger market cap than proof of work crypto.