A few reasons — and they all make sense once you hear them:

1. Canada is huge

We’re the second-largest country in the world, but most wineries are clustered in rural areas of the Okanagan, Similkameen, Niagara, and Prince Edward County.

Distance means extra time and gas and mileage.

2. Fuel prices soared

Wine doesn’t teleport. It needs trucks (or sometimes planes), and those trucks need fuel.
When fuel spiked, shipping did too.

3. Temperature control

Wine can’t freeze or cook in transit.  More on that in a moment. That means:

Winter shipping must avoid deep freezes

Summer shipping must avoid trucks turning into ovens.

The only fully temperature-controlled wine shipper in Canada is ATS, and they operate BC → Ontario/Quebec only (because they bring medical supplies FROM ON/QC and take wine from BC back east on the otherwise empty trucks). 

There are regional carriers in Ontario now offering some temperature or ambient controls for wines shipping within Ontario and out across the country, but often it is up to the winery to watch weather and be smart about when wines ship out. Temperature-safe shipping therefore often = higher cost.

4. Small wineries = small margins

Most Canadian wineries are tiny family businesses.
On a $20–25 bottle, a winery might only have $5–6 of margin to work with.
On a $100 order, they simply can’t afford to cover a $30–$80 shipping bill.

So who pays for shipping?

Historically: the winery.

Increasingly: the customer.

But ideally? A shared model that doesn’t kill small producers, or your wine budget.