Departure flights of Americans to foreign countries is up 2.9%. If that is indicative of the normal post pandemic recovery and travel growth then down 3.8% might be down roughly 6% from what it would have been. But it's possible the trend wouldn't match America's travel growth or more egress from America is being driven by related factors.

The decline of international traffic to Las Vegas from places like Canada are more noticeable

I can't read the article (paywall) - does the "international arrivals" include Americans travelling overseas, or only non-Americans?

If the latter, then indeed it's not dramatic. But if the former, then the number of contingent trips to the US might have dropped a lot, and is hiding mixed in with regular unaffected traffic of USians.

Here it says 14% drop in March.

https://www.ustravel.org/us-travel-snapshot-april-2025

Considering the effects of air travel on the climate, why would you not video conference?