My regular policy is to ghost any employer who throws a HackerRank test at me. This is usually a strong indicator that the work environment is incompatible with my values.
I politely tell them I'd be happy to have a call or phone screen with them, but I don't do automated puzzle-type tests. This gives them an opportunity to give me their side of the matter and also gives them a signal that at least one candidate dislikes automated puzzle-solving tests.
US companies ghost candidates all the time. They actually do it on purpose, partly out of a fear that explicit rejections (especially with reasons given) may elicit lawsuits.
Our applicant tracking systems won't be upset if you ghost them/us. Your application will simply expire after a while.
Recruiters acting in a professional capacity or companies, both of whom would ghost you without a second thought? I gotta say I don’t really see the problem.