My friend I know you just discovered nix but "don't have processes we don't need using cpu cycles" is low hanging fruit. If you really care then you'd use a bare linux kernel.

Of course mining is done on ASICs. If you care about latency you implement the network interface into the ASIC, and don't even use a CPU.

Parent's answer wasn't anti-crypto.

No it wouldn't, this is a fundamental misunderstanding of what mining is - the difficulty of mining scales automatically. Bitcoin went from CPU to GPU to ASIC and had massive efficiency improvements at each stage, but the total power consumption has only gone up. The nature of mining is that it prevents Sybil attacks by tethering consensus decisions to scarce physical resources, and so it only works if it keeps those resources scarce - the faster a block is mined, the more difficult the next one will be to keep the rate of blocks relatively constant.