I live and drive in the U.S. and the perception of what counts as being “cut off” is regional and correlated with density.

A maneuver that’s perfectly acceptable in NYC can earn you an angry honk in the suburbs. For better or worse, in large swaths of the US people are accustomed to having loads of space on the road and ample time to react to changes in traffic patterns.

New Yorkers would call other people lazy/inefficient drivers. Other people call New Yorkers crazy/aggressive drivers. YMMV.