Mostly, I agree, but two exceptions that might matter to some pilots:
1. If you're planning to arrive early/late or on weekends/holidays, your choices shrink. For example, at Kingston, ON (CYGK)—the only civilian airport near the US border between Toronto and Montreal that has precision approaches—regular customs hours are 9–5 local, Monday to Friday (excluding holidays). If You're CANPASS, you can clear there after hours; if not, you might be sweating it out after enroute delays, wondering if you'll squeak in before 5:00.
2. Some AoEs are CANPASS only, including my home airport CYRO. If you want to fly to one of those, CANPASS saves you an extra stop.
If neither of these cases applies, then agreed that you won't get much extra benefit from CANPASS.