Ask HN: Why that many more US-based companies are hiring "US-only" remote?

I recently got laid off and was going through the latest "Who is hiring".

I noticed that about 90% (guessing) of US-based companies that hire remote are hiring "(US only)".

I know there are plenty good reasons for a US company to hire US-only, I am only surprised because a few years ago (when I last was searching for a job), that was definitely not the case. "US-only" was the exception, not the rule. At least in the universe of companies that post on "Who is hiring".

What prompted the change?