Are other airlines like AC, Delta and others also having seat sales?
Yup!
Are other airlines like AC, Delta and others also having operational issues (which is sometimes connected to airport authority operational issues, which is out of the airline’s control)?
Sure are!
So Westjet may be incompetent”, but then so must be AC, Delta, and other airlines.
This is a round the world problem, stemming from the pandemic and the after effects of it. Staffing, supply chain, and more. Not just at Westjet.