the Bay - Cookware and kitchen essentials sale - worth it?

Only if you need it now. Better sales may happen during BAYDAYS.

the more I read, the more people are saying these cookware sets, regardless of the sale price, are no good

The regular prices at bay or Canadian tire are meaningless. They grossly inflated the regular price. Often times you can find the same item cheaper elsewhere at regular price. Their sale price is more or less similar or slightly cheaper than regular prices elsewhere. Honestly shopping at the bay or Canadian tire, if it’s 70% off, I would consider it as the actual regular price. So 75%+ off would actually be a sale. There are exceptions but that rule applies for majority of stuff both stores carry.