Trade barriers are trade barriers. Free trade means no barriers, not no tariffs specifically. Anything that makes doing business in another province more difficult than regular operation in your own province is a barrier to trade.

Agree completely. The most common barriers to trade are tariffs and I'm glad we don't have those within Canada. The next most common barriers are regulatory and legislative and we've got those but the good news is (unlike the US-Canada trend lately) those barriers are diminishing (at a government pace) in a consistent trend over time.

I'm not aware of steps backwards (as in US-Canada relations) where barriers between provinces increased. Am I wrong to be optimistic?