Who ultimately decides whether it is safe for flights to operate in specific weather conditions at an airport?

While airports have control over operations, the decision about whether it's safe to operate in specific weather conditions is ultimately determined by pilots and airlines, not airport authorities. In the case of the Delta Airlines incident at Toronto Pearson Airport, visibility was good, but wind was the problematic condition. Despite many flights being canceled in the days leading up to the incident, on that day, some operations resumed as they felt they could catch up, which raises questions about the decision-making process during adverse weather.