Sure, but they aren’t “entirely different experiences” - they are pretty much identical experiences just VIA is a little better but you pay for it.
Pre-COVID:
VIA - real china, cloth table linens
Amtrak - plastic plates and paper table “cloths”
VIA - Different menu for every meal
Amtrak - Same menu for every meal (often the same in both directions, and across multiple trains)
VIA - Complimentary alcohol (for sleeper passengers) with the meal
Amtrak - one free can of soda. Alcohol extra (wine tastings had been discontinued before COVID)
VIA - Appetizers, snacks, drinks distributed to sleeper passengers between meals.
Amtrak - Feel free to visit the cafe car and buy a shrink-wrapped brownie or a can of Budweiser.
I suppose the quality of the food itself served in the diner is subjective. I’ve only done a couple of trips on the Canadian (one Edmonton-Vancouver, one Vancouver-Toronto), but it my impression was that the food was better (not sure if it was the selection, or if I just got lucky). Amtrak diner food in recent years has felt like Denny’s, at best. Maybe the main course was good, but Amtrak’s pre-meal salad has been sad for a while, and the side vegetables were okay, at best.
VIA - exclusive dome cars for sleeper passengers (sometimes multiple cars, depending on load)
Amtrak - sightseer lounge free-for-all. Eastern trains, there’s the sleeper lounge (Viewliner diner), but significant food downgrade. Prior to the food downgrade, your “lounge” was an Amfleet II cafe car.
But other than all of that, probably identical.