Of course, that rule is very strict.
Many people work two or three jobs precisely because they want to accumulate more hours of work, but one of those jobs may end up causing them a problem. People often try to take a new job to get more hours of work. However, when they leave the new job to return to their previous job, Service Canada considers it a voluntary departure. Unless Service Canada accepts otherwise, those people automatically lose all hours of work that could qualify them for employment insurance. If someone has three jobs and leaves one, they lose the accumulated hours for the other two jobs. The person loses all the hours of work from all the jobs they have held. That's a very strict rule.