I don't have any data for <100 miles, but I've gotten stuff across the country in 3-4 days at the basic rate, 2000 miles not just 100 miles. And there are options for next day delivery, it's not like it's not available.
Canada's low and spread out population has to count for something in this argument.
You can get stuff across country in the US in 3-4 days too. And I didn't say there weren't economic/geographic reasons why Canada's mail service isn't as good, just that it isn't as good.