I don't think it is really necessary to do a formal "program", if you can work through all the big topics effectively together. On the other hand, a lot of people probably need help with that so I can see their value.

I suspect that unless you as a couple are already aligned with a religious provider of this counselling (e.g. the same church), a secular service would likely be more effective. Not inherently, just more a fit with the particular couple.

Which does sort of beg the question about why its not a more common discussed option? I mean, for a couple to seek out pre-marriage counselling outside of a religious context? Or even discuss it as an option.

I've known several couples who did such a program but they were all doing it at the request or insistence of their particular church. And I've known several couples who have gone to (secular) marriage counselling, but only after the fact.