I don't agree that you 'sign up' for being woken in the night when you have a baby. Yes, for the first six months or so, but once a baby goes onto solid food there is no need for them to wake for food in the night.
They may wake for comfort, but if you do gentle sleep training you can 'wean' them off needing that comfort in the night. That is better for parents and kids.
I agree with co'sleeping, I didn't do it very much with my twins (logistical nightmare) but plan to do it with no.3 for the first few months. But after that it will be sleep training to get them to sleep well on their own. I believe that is better for the child as well as me.
My SIL has a 20mo who wakes each night and takes about 2hrs to re-settle. It also takes her an hour or two to get him to sleep in the first place. She cuddles him until he falls asleep then puts him in his cot when he invariably wakes again and she is back to square one with the cuddling. She is exhausted after 1yr+ of this.
I don't think you 'sign up' for that when you have children. I would be on my knees now if my twins didn't sleep well. It's hard enough to look after them without being sleep deprived too. When they wake in the night they just sing/chat and then go back to sleep.