My point is that they tried it without a mandate already. North Dakota, Arizona, Iowa, Arkansas, etc. States without mask mandates saw cases spike, ICUs filled up, health care workers started getting sick, things got scary, and they were forced to implement mask mandates before reaching the point where there was zero available healthcare capacity for non-COVID issues.
Why have so many states that initially refused mask mandates had to turn 180 degrees and mandate masks? Because nobody was wearing masks without the mandate.
Trump failing to encourage mask use is an active decision not to intervene. You seem to be saying that by failing to invade Canada, we have intervened in Canada.
Or maybe I missed your point? That's definitely a possibility.
I think the disagreement rests on this point. From my point of view Trump has done vastly more than not intervene.
The President of the United States has gactively discouraged* mask usage.
That is why states have decided they need mandates.
From my perspective, it seems like you come to the same conclusion.
While you say that "Unfortunately mask compliance on this side of the pond has largely been a result of government intervention" it is also clear that non-compliance is largely a result of government intervention, eg Trump and others failing to encourage mask use, and both side weaponizing the issue.