Wait times are definitely a factor. The situation is different now, but before the pandemic, the wait times for a permanent residency were twice as long in Quebec as they were everywhere else in Canada. Obviously, when people asked me if they should go to Quebec or Canada, I would tell them that things would move a lot faster in one than the other.
Again, some of these people are arriving from countries that lack the same level of government services that we provide, or lack the same relationship with them. They do their best to prepare their application, which is often quite lengthy, only to receive a one-line letter in return. They learn that their application has been turned down because it's not thought to be a good one. All the rest of the letter is copy-pasted. They try to figure out what happened, but have no access to anything. I think that discourages them fairly quickly. If they have the option of going to France or somewhere else at that point, they will.