That's a valid reason to serve JS-based PoW systems scares LLM operators: there's a chance the code might actually be malicious.
That's not a valid reason to serve JS-based PoW systems to human users: the entire reason those proofs work against LLMs is the threat that the code is malicious.
In other words, PoW works against LLM scrapers not because of PoW, but because they could contain malicious code. Why would you threaten your users with that?
And if you can apply the threat only to LLMs, then why don't you cut the PoW garbage start with that instead?
I know, it's because it's not so easy. So instead of wielding the Damocles sword of malware, why not standardize on some PoW algorithm that people can honestly apply without the risks?