I would think that many children seem to feel safer and more secure sleeping in the same room as their parents if not the same bed.
They do. You can imagine from a child's pov wondering why they have to sleep alone when mummy and daddy have each other and get to sleep together or in the case of a single parent, why mum/dad get to have someone to stay with them at night while they (the child) don't.
It does make them feel lonely, if not unwanted, till they become conditioned that it's the done thing and learn from everyone else in the culture that it's normal.
So why do we force them to go against what seems to be so natural for them?
Culture, tradition and it's born from selfishness (I don't mean this as a bad thing necessarily) - needing your own space, needing space for sexual activities, needing time to rest and relax from taking care of them. It's definitely not for any child benefit reason.
"To get them to be more independent", my fat arse! What, at 2/3/4... years old?
Children generally tend to move away from wanting to sleep in the same room as their parents after a while and they also have very similar reasons as the adults, which is that they need their own space but adults generally don't wait to get to that stage because of the culture.