Has anyone been to a land border crossing in the pandemic? I'm a dual citizen, and have traveled back and forth five times since March 2020.
The US side is not at all prepared to Covid screen. To me that is the #1 reason Canadians can't drive into the US. Air travel already had more security and more requirements, and you can do a lot before you arrive at the airport. There was already digital infrastructure, which is why you can check in for a flight while still at home. The land border is not set up for all that testing and vax information, there is no correlate to ArriveCAN. Then I think there being no uniform, easy to assess Canadian Covid "passport" makes it even more of a hassle before you consider the additional issues that currently the US doesn't view AstraZeneca or mixed dosages as valid vaccination.
Meanwhile, Canada either does not think people like me exist or wants to be so punitive to deter me from seeing my family that they don't think anyone would actually go for less than a week. My last trip, my first with the testing requirement to re-enter Canada, was my usual three-day stay, so I literally crossed into the U.S. and went straight to my Covid testing appointment for a test that only proves that I didn't already have Covid in Canada before I went to the U.S.
I saw zero American license plates on the cars waiting to enter Canada. No one would go through that much trouble for the usual border-state day excursion into Canada. Only people with property or family, people with a real compelling reason to come and stay for at least a week.
I don't think Canadians will want to do all that to pop over to Buffalo for a couple of days of outlet shopping while they wait for test results to come back (mine took a full 48 hours). So the border states that want and need Canadian travelers won't really get what they want until and unless vaxxed Canadians don't need to have test results in hand at the border.