What age should kids sleep in there own bed?

i have little brothers that are 6 and 8 & they still sleep in the same bed as my mom even though they do have there own room idk but it just looks sick to me i mean when me & my oldest brother were little kids we never slept in bed with my mom we always slept in our own rooms like wtf its just weird to me idk also my little brothers that are 6 and 8 still get fed like they don't even pick up the spoon and feed themselves & when me & my brother were little we were more independent & fed ourselves and did things on our own i don't really get it :-/