I don't know for sure if this (vegan) Viro Fascist is correct and that Americans driving to Alaska are allowed to enter Canada despite the border closure. However, if this loophole is correct than it's incorrect to claim Banff is not a stopover on the way to Alaska.
To get to Alaska there are two basic routes of entry: the Alaska Highway which runs from Dawson Creek to Watson Lake (BC Highway 97), and the western BC route (BC Highway 37) that runs from Kitwanga (near the home to the whiny Wet Soup Tribe) to Watson Lake. It's worth noting that the western route requires you to go to Prince George first: from there you can use Highway 97 (you miss Dawson Creek but do join up at Fort St. John) which is faster, or you can go through Houston and then Highway 37 which is shorter:
. If you come up from the south to Prince George you'll be probably coming up from Abbotsford or Osoyoos. In that case, yes Banff is definitely not along your way.If you're coming up from Kootney area border crossings (Trail, Eastport, Eureka) then you'll almost certainly want to go through Banff: it's shorter and faster than the route to Prince George via Williams Lake and 70 Mile House, or the route through Calgary:
If you're coming through the Alberta crossings you'll almost certainly go through Calgary (an eastern Alberta route through Taber and Hanna exists in case you're also on a Nickelback and corn themed trip), and yes it's shorter and faster to use the western Alberta route through Sylvan Lake and Winfield but apologies to the Bluffton Rock but I think the Banff and Jasper is slightly more scenic...
I think that's worth the extra hour and a half and 150km worth of gas: you get to take the incredibly scenic Icefields Parkway and you don't have to look at this:
Now granted if the American is coming up from Winnipeg or points east and aren't going through Calgary, then yes Banff is out of their way (even from Estevan Saskatchewan it only adds an hour or so to go through Calgary which more Americans have heard of). This (possibly allegedly) Texas loophole-finder did nothing wrong.
