I don't know if PoW based approaches make much sense in the modern environment, anyhow -even very clever ones that provide ASIC resistance. Ethereum has been doing real proof of stake (and not delegated proof of stake which is both easier and terrible from a system safety perspective) for quite a while and it's seemingly cheap, effective, and robust.

PoW is useful in far more situations than PoS. A derivative of RandomX is now used to protect TOR too (Equi-X). https://github.com/tevador/equix/blob/master/devlog.md