A newborns instinct to survive gives them a physiological drive to seek out and stay close to their mother. They recognise their mother by smell long before they can see.
When with their mother their olfactory bulb sends messages to the brain releasing endorphins, soothing and calming them. This is all they know of ‘love’ at this stage.
Sound has a similar effect, but baby still seeks out smell because this means they are likely to be being held. (One of the reasons baby wakes when put down in their own sleep space).
When separated from mum’s smell and sounds stress hormones flood their body. Some babies will cry, sadly others will freeze or flop and look as if they are calm. Again this is a survival mechanism to stop them being eaten. A baby doesn’t know that they are living in 2023 and that society has moved on. A baby doesn’t know if can be fed from anyone but mum. A baby doesn’t know that they aren’t living in a cave with a real risk from predators. It just has a deep instinct that being with mum=survival and food.
So yes, unfortunately being away from your baby, without it being medically necessary, is cruel. You are putting them under huge amounts of unnecessary stress, whether they cry or not.
Some people being fine with it, is irrelevant. I imagine they are looking from the situation from a social standpoint rather than a biopsychological one. Babies couldn’t give a hoot about equality.
As a minor point I would also question your bond with baby, if you felt able to be away from them at this stage. The physiological compulsion to be with them is generally reciprocal (but not always).