There's really not enough money in this to make it a worthwhile revenue generator for the government. Let's look at the numbers.
Right now, a G licence road test costs $85 in Ontario. In order for the proposed system to work, they'd have to maintain a reasonable cost for these tests, otherwise, it would never fly. So, let's say every province and territory (since licensing is a provincial thing) has their test come in at an average of $100 per, and that every licensed drive needs to be tested every 5 years. There are ~21 million licensed drivers in Canada, so, that means ~$2.1B in total revenue distributed over 5 years or roughly $420M per year. From a government's perspective, that's already pretty insignificant. That $420M per year is distributed proportionally to the various provinces who are conducting the tests, based on how many drivers they have. Since Ontario has roughly 30% of the population of the country living here, we can probably safely assume they have a similar percentage of the drivers, so, that means they take in ~$126M per year from this. Now, we're talking about a government who deals with a budget that is in excess of $100B. ~$126M would barely register for them - and, we're simply talking revenue here, not profit. Once the expenses of expanding the system to this point are taken into account, there's really no money to be made by the government here unless they increase the costs or the frequency of testing well past the point where there'd be more pushback than it would be worth.