What's interesting is that none of these sites have a "search" feature. Which is an important accessibility feature and a clear and legitimate use case for a query string.

> If I ever start using any query strings, I’ll allow only known parameters.

They aren't saying the concept of query strings are bad, They're saying unsolicited query strings during referal are the issue.

My website has search without a query string: https://www.jeremykun.com/