That's one of the costs with having a public website.
I really like this take on moderation:
"The essential truth of every social network is that the product is content moderation, and everyone hates the people who decide how content moderation works. Content moderation is what Twitter makes — it is the thing that defines the user experience."
From Nilay Patel in https://www.theverge.com/2022/10/28/23428132/elon-musk-twitt...
I suppose a sufficiently motivated spammer might incorporate that as a submission workflow check.
Operators of public sites should NOT have to pay that tax. So you are best are not fully aware of the actual cost, IMHO.
Congrats to HN for striking a reasonable pragmatic balance.
*I had some of the first live (non-academic) Internet connectivity in the UK, and the very very first packets were hacking attempts...