Um - excuse me, but I think I was the one who said much earlier in this thread what we don't usually dare to say about nursery care. And what I said was more controversial .
I am trying to get my head around your rationale, Bonsoir.
(a) Baby/ toddler goes to nursery 5 days a week (not the ideal for them). Sees parents every day for cuddles, food, stories, bonding, etc etc.
(b) Baby/ toddler's parents go away for 7-10 days. Child gets phone calls, perhaps even video calls - reminding them what their parents look like - but doesn't actually get any direct contact for this whole time.
Most children, upon their parents' return, in situation (b), are distant with their parents - this is a psychological response to reduce anxiety. Some children do it in situation (a), but I'm willing to bet it's a far higher majority in (b), simply because the time apart has been so long.
Also the situation of leaving a young child with a family member is different from leaving them with a paid carer. A family member has a level of emotional and relational investment in that child which a paid carer simply doesn't have. This has a huge impact on the child's care, and, according to some studies, on the child's well-being. Nonetheless, even if left with a family member, the length of away time is still crucial at this young age.
The fact is that we tell ourselves all sorts of things about how 'good' nursery/ our going away will be for our children, as a way of assuaging our guilt. But we need to come clean - with ourselves at least - and admit that when we leave them at such a young age, it's really not all that good for them at all, but that's the choice we have made, whatever our reasons.