I think there is still a misunderstanding here. I'm not the person you originally replied to, but I read their message as having focus on the small team aspect.

I think there is still a misunderstanding here. I'm not the person you originally replied to, but I read their message as having focus on the small team aspect. If there is a team of, say, 2-3 devs, their rotations cycle would essentially be every 2-3 weeks. Even if it's only on their service, they'd still be on rotation every 2-3 weeks. Alternatively, if there is a wider group of people, the people on smaller teams wouldn't need to constantly be on rotation. I'm not sure if one is better than the other, but the assumption of only being on-call for services you own assumes some minimum team size, or as acceptance of being on-call every other week.