4 hours is a very long requirement.
I’ve had a schedule change to a domestic flight meaning I arrive on a long haul flight at 1525, and my connection which did leave at 1640 now leaves at 2050. Fortunately it’s 10 minutes over the 4 hours so I could cancel but if it had been 10 minutes less, I’m sure some would consider arriving at 10pm to be a significant change from arriving at 6.05pm, particularly if onward car or public transport travel was required at the destination.